Surface Resonance - RMIT Research Repository

Surface Resonance - RMIT Research Repository
SURFACE RESONANCE
Surface Resonance
A project submitted in fulfilment of the requirements for
the degree of Master of Arts
Eliot Samuel Palmer
Grad. Cert. Spatial Information Architecture
School of Art
College of Design and Social Context
RMIT University
January 2010
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SURFACE RESONANCE
Declaration
I certify that except where due acknowledgement has been made, the work is that of the artist
alone. The work has not been submitted previously, in whole or in part, to qualify for any other
academic award. The content of the ADR is the result of work which has been carried out since
the official commencement date of the approved research program.
Signature
Name
Eliot Palmer
Date
20/06/2010
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SURFACE RESONANCE
Acknowledgements
I would like to acknowledge and extend many thanks to Larissa Linnell, Dr Philip Samartzis,
Jason Heller, Brian May, Eamon Sprod, James Hullick, Lawrence Harvey and Derek Marr for their
inspiration, advice, listening, support and proofreading.
I would especially like to thank Darrin Verhagen for his guidance and engagement, Garth
Sheridan for his consistent support and heavy lifting, and Nic Whyte for website expertise and
assistance.
Thank you also to the staff at Warehouse Sound Systems, Tim Catlin and Michael Quinlan at
RMIT, and the participants who gave feedback on the vibration compositions and approach to
installation.
Online resource
This ADR will be reproduced at http://surfaceresonance.croakinglizard.com, in an html format
with the text supported by images, sound and video.
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Contents
i. Summary
ii. Contribution to the field
iii. Background
4
9
14
Phase 1
Phase 2
Phase 3
Phase 4
Phase 5
Summary
1.1 Riddim
1.2 Materials
21
25
28
Summary
2.1 Materials
2.2 Tactile instrument
2.3 Riddim
2.4 Presentation
31
35
37
39
41
Summary
3.1 Tactile instrument
3.2 Hearing and sensation
3.3 Materials
43
47
49
51
Summary
4.1 Materials
4.2 Hearing and sensation
4.3 Tactile instrument
4.4 Riddim
56
59
60
61
66
Summary
5.1 Hearing and sensation
5.2 Materials
69
73
74
Phase 6
Summary
6.1 Riddim
6.2 Materials
Presentation context
77
81
85
89
Appendix A Background research notes
Appendix B Bibliography
Appendix C Discography
Appendix D Original proposal extract
95
103
105
107
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Summary
i. Summary
Surface resonance is a sound and tactile sensation research project. Through compositions and an installation, I
focused on felt and heard vibration, how they are perceived and how they contribute to the experience of sound.
I explored vibration as a product of low frequency (bass) sound, drawing inspiration from musical contexts
where sensation from sound is emphasised. As low frequency sound passes through a space it can stimulate
vibrations in a building structure. These vibrations may be experienced physically, through the transmission of
energy from the building and into the body, and/or may create vibration sound that is experienced aurally, such
as rattles from fixtures or windows.
My interest has been in the characteristics of these vibrations and how they may convey connections between
sound and the physical aspects of the body or a space. I have explored the idea that vibration, both heard and
experienced physically, can change a person’s perception of sound.
Compositions were made for vibro-acoustic installation, which combines a ‘tactile table’ system that an audience
sits or lies on to experience sensation, with loudspeakers reproducing acoustic material. This ADR supports the
evaluation of the compositions by giving body to the research program. It also provides a resource for composers
working within the field. It describes the questions asked, the methodology applied, and the outcomes.
Given the vibration medium, the descriptions can only partly illustrate the creative process and findings.
However, a focus on my conceptual development and research process is provided to show the ideas covered and
contribution to the sound arts field.
Research question and aims
My project objective was to develop
compositions for installation that communicate
my findings on felt and heard vibration. I
aimed to create works that drew association to
listeners’ past experiences and engaged with
the way vibration is perceived.
At the beginning of the research program, I
asked:
Through sound design and composition
incorporating sensation technology, how can
I use physical vibration to draw attention
to the role of the body in the experience of
sound, and how can I draw upon vibration in
musical contexts to achieve this?
The question sustained throughout the project,
and developed into four key principal research
aims or foci, framing my research approach
and helping to define the field covered.
These concerned:
• abstracting musical basslines into an
environmental domain
• articulating building materials through
vibration
• composing for a tactile sensation bodily
experience
• understanding the dialogue between hearing
and sensation, and how felt and audible
aspects affect awareness and perception of
each other
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Summary
Loudspeakers generate audio
for listener
Amplifier - for
loudspeakers
Vibration table generates
vibration sensation
for listener
Some sound
also generated
Amplifier - drives
the table ʻvibration
acutatorʼ like a
loudspeaker
Computer multi channel
audio signal
outputs
Eliot Palmer - Surface Resonance - ADR
Overview of how the
vibration table
is experienced
Masters Sound Art
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Summary
Principal approaches to research and
composition
Audio composition
I designed a 1.2m2 ‘tactile table’ system that
translates sound into strong vibration that
may be felt through touching or standing on
it. Amplified audio signal is fed into the table,
which incorporates an audio-signal driven
‘vibration actuator’ in place of a loudspeaker.
To explore ‘vibration sounds’ from materials, I
started by recording music-activated vibration
in spaces. My practice developed from this to
using the vibration table to ‘excite’ material into
resonance, particularly large building materials
such as window panes and sheet metal.
Vibration composition
Recordings of this were the basis for acoustic
composition, made to partner with the
vibration material.
I experimented with and composed vibration
material for the table, exploring how an
audio signal is presented through a tactile
medium, and how vibration requires a unique
compositional approach.
I assessed aspects such as how higher
frequencies were reproduced, the dramatic
changes in perceived level and upper
harmonics with small changes in signal
level, and phase interferences between low
frequencies.
To make sounds through materials, I combined
table-based vibration with hand dampening to
alter the vibration behaviours. I also explored a
range of miking techniques.
I tested the spectrum of sounds that may
be generated, from metallic resonance, to
discordant and distortive sound, to more
subtle vibration sounds at the periphery of low
frequency sound.
Much of my research development came from
exploring the kinds of experiences and states
I could communicate with vibration, and the
component parts that make up an effective or
engaging sensation. This helped me develop
a distilled approach to composing sensation
material.
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Summary
Vibro-acoustic presentation/installation
I explored the relationships between vibration
sensation and hearing, and how when
experiencing a vibro-acoustic composition,
each sense can affect perception and awareness
of the other.
The final works engage both the auditory and
tactile senses, by involving audience interaction
with the table to experience sensation, and
loudspeakers that reproduce acoustic material,
derived from objects brought into resonance.
I tested different vibro-acoustic relationships,
such as sound and vibration aligning to each
other, to more ‘contrapuntal’ structures.
By working with the crossover between hearing
and whole-body vibration perception, and
applying a range of vibration experiences
and effects through the table, I developed
compositions that establish a dialogue between
hearing and sensation.
The initial inspiration –
musical vibration and riddim
the body is gripped and released with different
tones and intensities; and a performance space
responds in different ways as it is activated by
the shifting bass sounds.
By looking at this music and context as a
reference point, I drew upon the unique
properties of vibration within music
experience, such as its strong physical aspects,
and its tonal/rhythmic qualities.
I explored how effectively I can rearticulate
and abstract riddim-based vibration in
creation of sound art works, and tested the
issues associated with this linkage to musical
contexts.
I focused on the natural processes of abstraction
that occur when music passes through a
building and creates audible vibration; and how
the resultant sound can shift from being musical
to unfamiliar, or registered as environmental in
nature.
My research drew from and was influenced
by environments with a strong and unique
association to felt and heard vibration.
While the exploration of riddim was a common
thread in all of the aspects of my research,
at the conclusion of my studies I arrived at a
point and creative approach that was highly
abstracted from this musical reference.
These are specific contemporary ‘dance’ music
performance contexts, where high levels of low
frequency sound (as bass in music) stimulates
physical responses from the body and the
architectural environment.
For audio compositions, I attempted to retain
a sense of the way musical riddim activates a
space, with the varying bass notes triggering
different parts of a building into temporary
resonance or vibration.
In particular, I attempted to capture, reference
and abstract bass-line rhythm in dub and
dub-influenced music. Throughout this ADR,
I apply the term ‘riddim’ to encapsulate this
concept. ‘Riddim’ is about powerful, rhythmic
bass, with a lilting ‘drop’ where sensation in
For sensation composition, I aimed to deliver
an experience that alluded to the properties of
bass-heavy riddim engaging with the body.
At various stages, I experimented with stripped
back, abstracted and processed bassline riddim
for a bodily vibration experience.
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Summary
These tests informed a broader research arc
that explored other vibration sensation content
that could indirectly allude to music riddim.
This covered bass heavy drones, modulated
low frequencies, tests with tactile feedback,
and building riddim-like patterns of bass from
flange and phase processing of pure bass tones.
At the end of the program, I established
effective approaches with slowly undulating
vibrations.
Conclusion of the research program
To most effectively answer my research
question, I concentrated on testing and
developing new understandings within less
explored aspects of a broader domain.
For example, my compositions are in the realms
of full-body tactile and combined tactile and
audible experiences, while recognising the
work of artists exploring low frequency sound
sensation. With sound, I concentrated on
generating, articulating and recording surface
vibration, with an appreciation of the artists and
works investigating space and object resonance.
In concluding my Masters program, I have:
• thoroughly explored my research question
and aims
• contributed new works and ideas within
the larger field of sound art employing low
frequency sound and vibration
• developed a solid basis for a broader
practice that can build on my findings and
contribution to the field
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Contribution to the field
ii. Contribution to the field
This section describes the relationship of my work to others in the field. I separately describe the aspects of
the vibration sensation experience, making sound from vibrating materials, and the combined vibro-acoustic
experience.
The key elements that situate my work and mark its contribution within the field are provided first. Following
this is an outline of other cited artists and works within the broader domains of tactile work and vibration
sound.
Contextualising the work
Vibration sensation experience
The central body of my work concerned
understanding and composing for the tactile
experience. This was for both vibration-only
and vibro-acoustic works. I used the vibration
table as a means of communicating vibration
and also as an instrument itself, focusing on its
particular attributes as a sounding device.
My compositions for a deep, very low
frequency bodily experience have
commonalities with a number of sound artists
[for example, Randy Yau and Scott Arford’s
Infrasound performances, Zbigniew Karkowski,
Francisco Lopez], as well as connections to
deep bass sensation in riddim music (dub,
drum and bass, dubstep etc.) and other deep
sensory music and experimental performance
artists such as Sunn O))) and Cat Hope / Lux
Mammoth.
and experiences not being translatable
from one sense to the other. My research is
underpinned by my interest in this relationship,
including understanding the crossover between
sensation and sound perception.
My decision to use the table as a standalone,
portable sounding sculpture aided this
concentrated exploration of sensation
experience. It offered a way of developing
and expressing ideas that were not reliant on
stimulating whole rooms through massive
audio systems. The participant experience
was more internalised and personal than
architectural.
I composed a broad range of vibration gestures,
developed targeted approaches to making
source material with sensation as the primary
aim, and worked with the specific vibration
and audible characteristics of my constructed
table, as an instrument.
The fundamental difference between my work
and the rest of this domain is the different
experience and compositional language I
offered through explicit tactile sensation,
compared with sensation as a product of low
frequency sound.
I am aware of, but have not been able to
directly experience, the work of other artists
using body tactile transducers [for example,
Patrica Piccinini’s the breathing room,
Recombinant Media Labs, Michael Luck
Schneider and Bruce Odland’s work, including
for the Good Vibrations Caravan].
While there is a broad crossover in the
experiences, there is a very different textural
scope in tactile sensation, with many gestures
Compared to these artists, I consider that by
working with a dedicated vibration device,
in a long-term experimental sense, rather
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than in an installation or for a performance,
I have been able to offer new experiences for
audiences.
This is particularly the case where I have
focused on discrete components, including
rhythmic elements, stutters and plosive effects,
rather than longer arcs, such as modulated
sine tones, which, from my readings and
discussions in this area, I understand are more
typically employed in installation works.
Also, I have focused on vibration as a
standalone experience, rather than using
vibration devices to deepen an existing audio
or audio-visual experience, as appears to be
the case with some cited installations. It is in
such areas, and the research around separating
the vibration and acoustic elements from their
normal bound relationship (see below), that I
have contributed to the field.
Perhaps the most relevant artist in this area
would be Mark Bain, who uses transducers
and complex vibration tones to activate
performance spaces into vibration. In
these installations, the connection between
architectural vibration and tactile vibration
would be most explicit.
Making sound from vibrating materials
When approaching sensation I focused on
an internalised tactile experience delivered
through the table. This focus extended to the
way I approached the excitation, manipulation,
recording and presentation of vibrating
materials. I used the table to generate vibration,
and shaped sound in a close and personal,
bodily interactive sense, rather than a spatial /
architectural sense.
Contribution to the field
I have developed my own compostional
practice of articulating materials through
bodily engagement with vibration. For
example, to shape vibration sounds I applied
my body weight and pressure across large
vibrating surfaces such as window panes and
sheet metal.
(Conceptually, James Tenney’s Koan: Having
Never Written A Note For Percussion guided
my focused exploration of the changed state
of surfaces as they are subjected to different
intensities of vibration stimulus.)
This process was about expressing the
potential for surfaces to be excited into
vibration. This vibration can be a harsh,
discordant and inharmonic type of sound,
that is by its acoustic behaviour inherently
and harmonically tied to the deep sound or
vibration that has caused it, and underpins it.
My approach of hand dampening to ‘contain’
the vibration sound has enabled me to skirt
around the edges of discordant vibration, and
express a potential-vibration state.
This control, combined with the use of varying
and complex vibration tones, provided a
different character and depth to the sounds
than what is achieved through single-frequency
vibrators or offset motors, such as in David
Bryne’s playing the building installations.
The sounds created are also largely different to
the object-vibration works I have cited, which
have tended to use smaller scale materials (see
‘artists and works’ below).
The aesthetic also contrasts with sound-making
using percussion (striking) to generate sound,
such as in the glass percussive works of Eugene
Ughetti.
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The vibro-acoustic experience
The preceding information outlines the
primary components of my investigation.
However, my composition-led research may be
best understood through the combined vibroacoustic experience I offered to an audience.
To make sound and vibration I developed
content that referenced the ‘bound’ experience
that occurs when deep vibration travels
through a structure and into the body, and
what this evokes in a listener.
The music environment, as a starting reference
point, is an example of where high intensity,
low frequency sound stimulates buildings and
bodies into vibration. In this situation, the
‘bound’ experience of sensation and audible
building vibration of large materials is most
explicit.
Drawing from this experience offered a
perspective into the spectrum of situations
where low frequency waves stimulate the body
and architectural structures into resonance
and vibration (whether a musical, vehicular,
environmental or mechanical source),
sometimes in ways that are barely perceived, or
noticed only in passing.
My approach involved making sound from
large building materials, such as window
panes and sheet metal. This focus helped me
to maintain a clear reference to the vibration
sounds caused by music within a performance
space, and to explore the other low frequency
resonance and vibration sound contexts.
Contribution to the field
these an integral part of a bodily experience,
I was able to tap into an existing frame of
reference and ground the audience experience.
In the sections above I describe linkages from
my work to artists using intense low frequency
sound to activate spaces and bodies [Infrasound
etc.]. These areas have much in common with
my approach. However, previously described,
I have explored a more internalised, personal
experience by targeted stimulation of materials,
their recording and their reproduction in an
installation context.
This enabled me to contribute new works
with a finer control over the sound / sensation
dialogue, including controlled expression
through the table and the materials it
stimulates.
Importantly, my work involved separating
and challenging the traditional or expected
sound-sensation relationships (i.e. those made
where sound creates the sensation and the
vibration-sound, as parallel aspects of the same
experience).
Using the table alongside pre-recorded
vibration sound enabled me to play with
a range of vibro-acoustic relationships,
including synched, ‘contrapuntal,’ and more
subtly separated approaches. This offers new
experiences for an audience that draw focus
to our ordinarily subconscious perceptual
processes.
By focusing my audio compositions on
expressing the range of sounds that can occur
from ‘activated’ building materials, and making
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Contribution to the field
The broader field
Artists and works - vibration sound
In considering this area, it is important to make
a broad distinction about the areas of vibration
and resonance that I have focused on.
As previously described, I have drawn from
and referenced works and situations where
deep low frequency sound activates spaces
and bodies into vibration. This use of intense
low frequency sound in a space also crosses
into the area of expressing room resonance, as
emblematised by Alvin Lucier’s I am sitting in
a room, and works referencing this approach
such as Jacob Kirkegaard’s 4 Rooms.
However, I have chosen to concentrate on
object vibration and resonance of surfaces (as
parts of a space), rather than this architectural
resonance (such as standing waves) aspect.
The following describes inspirations, works
and artists in the field of object vibration and
resonance.
All of these are areas of interest, some of
which I intend to explore further in my
future practice. My particular approach has
acknowledged the strength of work in this area
and focused on less explored approaches and
materials. In doing so, the sounds and aesthetic
I developed do, in part, offer new experiences
within what is a well-explored domain.
The chosen approach and materials have
also been integral to addressing my research
objectives around the combined vibro-acoustic
experience and how this can draw from realworld experiences of body and object vibration.
An initial source of inspiration was the
way that basslines in music could create
vibration in spaces and loudspeakers. I drew
from the work of producers that embrace a
‘distorted’, vibration-like aesthetic in their bass
compositions [for example, Jah Warrior, The
Bug, Scorn]. I was also interested in producers
working with abstraction of the rhythm of
drums and bass [for example, Hrvatski, The
Artbreaker].
This connection extends to other bass driven
rhythmic compositions outside of a direct
musical sphere [for example, Carl Michael Von
Hausswolff ’s Strom], including works of Koji
Asano exploring the properties of loudspeakers
as a prepared, distorted or torn expresser of
sub-frequency energy.
From this reference point, I was interested in a
range of work in the area of smaller prepared
objects activated into vibration through
loudspeakers or vibration transducers, such
as Untitled Sound Objects’ work with metal
plates, beads on a surface, and vibrating
paper; Jeff Jerman’s Instability Studies with
‘shaketables’ and exploration of vibration and
harmonics in instruments and materials by
Tim Catlin and Jon Mueller. Vibration and
resonance in objects is also richly explored field
recordings, in particular by Toshiya Tsunoda.
I have also cited a work Clicks and Cars, by
Foton, using vibrators to excite car frames into
resonance, although I understand that this did
not involve body or hand articulation.
My approach to building sound/sensation
compositions gravitated around an
underpinning deep low frequency sound/
vibration, and building upon this, upper
harmonic (and inharmonic) audible material
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made from the excitation of objects. An initial
inspiration for this ‘fundamental frequency’/
’harmonic’ thread within my work were
works and interviews with Alan Lamb, on the
resonance of telephone wires.
Other fields of research and application
Contribution to the field
Finally, my vibration work has commonalities
with vibro-acoustic therapy, an area where
deep relaxing sensation is used to treat patients
with sensory impairment or other physiological
difficulties. While not within the realm of my
research question, I would eventually like to
explore this area further.
From a research perspective, whilst my work
contributes to current knowledge in scientific
research for music applications focused on the
sound/sensation dialogue (see background
below), my personal approach was to use
knowledge in this area to facilitate creative
expression, rather than to add to current
academic texts.
The use of tactile transducers has obvious
relationships to a range of other applications
for vibration devices. These include gaming,
theatre and nightclub applications. However,
my compositional research was much more
acute that the typical ‘commercial’ applications
where sensation is an augmentation or
supplement to the overall experience of sound
and/or vision, or a basic shaking or explosive
effect for the authentication of activity.
Being designed for the whole body, my area of
work also differs from use of tactile transducers
for communication by more localised touch
(such as the hand held dual shock controllers
in computer game systems). Early research
enabled me to distinguish my work from this
area from an academic viewpoint (also see
background) , as the modes of communication
and experience are very different from each
other. For example, engineering texts make
a categorical distinction between hand and
whole body vibration, as one is more to do with
touch, and the other body effects.
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Background
iii. Background
The sound art research program developed from applied research into low frequency sound and sensation
perception. I was interested in the way the body processes sensation and the dialogue between the senses.
This section is a reference for discussion of vibration perception within this ADR. It constitutes the findings of
research undertaken before the commencement of Master of Art studies.
The Master of Art candidature developed
from a Graduate Certificate and preliminary
Masters research at the Spatial Information
Architecture Laboratory (SIAL).
The initial focus was on using floor-based
vibration as a substitute for subwoofer
sound in a nightclub setting, and the noise
reduction benefits this would offer. I later
moved departments to refocus my work on the
creative potential of vibration technology.
This background research included:
• Relating soundscape studies to the
experience of low frequency sound in
contemporary music culture
• Researching sound therapy, sound
perception and engineering / noise studies
on low frequency sound and vibration
• Prototype design of a small, low frequency
sensation generating floor, and testing with a
group of participants
Research findings - vibration and vibroacoustic perception
The purpose of my research in this area was
to broadly understand aspects of vibration
perception that could inform my approach to
composition and installation.
Vibration perception
The processing capacity of the tactile system
has been explored in detail through research
with an industrial/noise focus, with key
literature broadly distinguishing between finger
transmitted and whole body vibration.1
The ‘loudness scale’ for vibration differs to
that of sound2, i.e. an equal increase in the dB
level of vibration and acoustic signal won’t
lead to the same perceived increase in level
across both senses. The vibration response can
be understood to generally be more ‘linear’
with stimulus increase, whereas
hearing perception is more like a
‘logarithmic’ function (as equated
in the dB scale for sound pressure
and audio signal).
Comparison of airborne with
structural vibration is an emerging
field,3 and research and anecdotes
around low frequency sensation
from soundwaves cannot be
assumed to transfer to tactile/
vibration perception.
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Some vibration studies were not directly
relevant to the whole body vibration focus
of my work, such as those of haptic feedback
for fingers or hands or skin effects. However,
I concluded that these could still be relevant
to understanding the way people process and
perceive vibration in a whole body vibration
context.4 For example:
• With skin vibration, different frequencies
carry different subjective effects, such as a
buzzing vs a smooth experience
• People have limited capacity to discriminate
different frequencies through skin vibration
• Perceptual effects can occur depending on
the type and closeness of vibration impulses.
For example, depending on the timing of
impulses, the vibration experience may
be enhanced, or signals may appear to be
summed together or suppress or mask one
another.
Vibration and auditory interactions
There is substantial frequency-range cross
over between the active range of vibration
and auditory senses, with hearing extending
below 20Hz (with loss of tonal perception), and
vibration ‘effective’ at a range of frequencies,
depending on its source and the type of body
connection (i.e. skin, whole body or finger).
Compared to the auditory sense, the tactile
sense is relatively lacking in sophistication.5
Studies on perception of timing6 7 8 of musical
auditory/tactile events found that:
• The auditory and tactile systems have
different processing delays before the signal
is recognised by the brain, with sensation
taking longer to process
• People will discriminate when the vibration
Background
and acoustic events are not ‘simultaneous’,
and may find this distracting
• The perception of simultaneity is not
absolutely precise. Within a tolerance
range (measured in milliseconds), sound/
vibration events do not have to be exactly
simultaneous to be perceived as such9
• The envelope of a sound has a significant
effect on the timing requirements for
perceived simultaneity,10 with a more
gradual envelope reducing perceptual
discrimination of timing offsets
• One study used an interactive touch/
feedback sensation with an acoustic system
in a virtual environment. Increased acoustic
level made people think the sensation level
had increased.11
Vibro-acoustic therapy and tactile systems
Vibro-acoustic therapies offer a range of
positive physiological and psychological effects
that come from vibration stimulation to the
body (usually while listening to music), such
as relaxation to muscles, pain relief, assistance
with brain disorders and injuries, and other
rehabilitation benefits.12
Vibro-acoustic therapy tends to use vibration
that either reproduces the low-frequency
parts of music, or uses pulsed sinusoidal
tones (such as from beat frequencies), in
line with the principle that ‘exposure to soft,
low frequency and non-rhythmic music...
results in physiological responses indicative of
relaxation.’13
Significant levels of high frequencies through a
vibro-acoustic system can lead to undesirable
or distracting acoustic noise.14
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When used in a vibro-acoustic system, the
vibration signal needs to be electronically
compressed (dynamics reduction) to
perceptually align to the acoustic information.15
Vibration floor testing
The vibration floor and soundsystem tests
explored how people respond to different
frequencies and intensities of low frequency
sound and vibration.
In each test, audio material was sent as sound
through a large subwoofer and loudspeakers,
and then sent through the vibration floor
instead of the subwoofer.
I interviewed participants about how the
Background
sensation experiences differed, their general
observations of the sound and their spatial and
bodily connection to it.
Testing used swept (fixed or pulsed) sine
tones, and a selection of bass heavy music with
contrasting frequency content.
The vibration/acoustic setup and ‘tuning’
applied findings from my journal research. For
example, I used:
• Equalisers and crossovers, to reduce
unwanted high frequency noise through the
floor, and roll off the acoustic level to enable
a smooth transition to sensation (crossover
point ~70Hz)
• Compression of the vibration floor signal, to
match the perceived vibration and acoustic
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levels
• Delays, to account for timing offsets from
the distance from the loudspeakers to the
floor, and sensory processing differences.
I refined these parameters through participant
feedback, and found that the ideal settings
accorded well with what was suggested through
other research.
The following test outcomes were the most
valuable to the ideas and methods I took to
sensation composition during the Masters
research.
Appendix A details these and other general
findings and the testing process.
Comparing modes of presentation
Using the vibration floor did not simply
replace the acoustic energy with a more direct
sensation interface. The qualities of sensation
were fundamentally different, being more
grounded in the body.
Overall, at most frequencies participants found
that they were more comfortable with vibration
energy than with the acoustic only system.
However, in the higher bass frequencies
acoustic and vibration energy became more
similar in sensation qualities.
Vibration sensation ‘bodily placement’
(localised sensation) did not correlate with
findings from the acoustic only system,
suggesting that the way the body is excited by
direct vibration is significantly different. Some
effects were specific to the vibration system,
such as a sense of the feet shaking. The range of
sensations experienced were broad, including
effects in the upper body, face, legs and back.
Background
In most tests the acoustic only system was less
enjoyable for participants. Because the acoustic
energy did not involve the body as directly, low
frequency information was less tangible and
less defined.
Compared to the vibration floor setting,
the sound-only setting led to additional
reverberation of low frequency sound within
the space. This significantly ‘muddied’ the
overall sound experience.
Interesting perceptual responses to sensation
The testing suggested unique perceptual quirks
when people experience sensation as vibration.
Participants reported the sensation as moving
around the body with different frequencies,
skin sensation, a sense of vertigo and a
feeling of tiredness occurring with specific
frequencies, and perceptual placement of
frequencies within the room.
However, these responses were not consistent
between participants, and there were not
specific frequencies with predictable effects.
I suspected that testing in open spaces or
specially designed testing environments may
have provided more consistent results.
Participants engaging with the direct sensation
Most participants quickly found that they
became more involved with music when the
vibration floor was engaged. In addition to
compelling more attention to the music, the
floor itself became something to interact with
and was missed when deactivated.
Descriptions included: the floor creating a
nicer experience because sensation was more
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SURFACE RESONANCE
bodily, feeling more involved and consumed,
increased awareness of high frequency sound
(in its relationship to the sensation), increased
awareness of low frequency sound, quick
association with the vibration experience,
and that the floor created another level of
interaction or relationship.
Frequency
Each music test track had a different frequency
emphasis. Participants favoured pieces with
frequency content extending into the very low
frequencies (20-45 Hz), where the contribution
of the floor was felt to be more essential.
Tracks where frequency emphasis was centred
closer to the upper operating frequency of
the floor (~85Hz) still benefited. However,
vibration effects were noticed as ‘buzzing’ or
were perceived to be located in the floor, rather
than a logical extension of audible sounds.
This may have been partly due to the type of
technology used (modified loudspeakers rather
than dedicated vibration actuators).
Participants found that when the low frequency
information was distinctly different from
high frequency information, the floor failed
to enhance the music experience. Rather,
with auditory and vibration senses processing
separate information, the floor became a
distraction and could be disorientating due to
lack of cohesion.
This was primarily noticed on one track, which
had an atypical gap in information between
low and high frequencies. All other tracks
contained some degree of acoustic ‘artefacts’
in the upper harmonics of the predominant
(vibration sensed) bass information, which
possibly aided in tying sensory information
together.
Background
Envelope
Participants favoured the vibration interface
in tracks where low frequency rhythm was
not overtly punctuated (i.e. having a rolling
or fuzzy quality). More punctuated rhythm
appeared to highlight differences between
acoustic and vibration information, perhaps
because the chronological space of definite
‘beats’ promoted more critical perceptual
processing.
This result was consistent with the findings of
William Martens on envelope and timing delay
tolerances.16
Dialogue between the senses
Feeling the bass as vibration sensation ‘muted’
auditory sensitivity to the complementary
sound. Most participants did not perceive
acoustic energy in the room until acoustic
levels were much higher than the normal
perceptual thresholds.
With sine tests, most of the participants
identified the same frequency point (56-57Hz)
where the energy shifted from vibration to
acoustic borne.
However, while this correlation was notable, I
suspected it was influenced by the specifics of
the testing room and audio setup. For example,
room modes and resonances, and the slightly
uneven frequency response of the loudspeakers
at the crossover points would have affected the
audio levels around the room, depending on
the frequency.
One participant identified a frequency where
they felt that their focus was flipping between
the vibration and acoustic system, at a point
Page 18
SURFACE RESONANCE
where both energies were perceived to be at
similar levels. This suggested that, although
there is some degree of perceptual blending
with combined vibration/acoustic energy, the
potential exists for sensory confusion when the
two sources of information are similar.
Similarly, tests with music tests tracks
suggested that vibration and acoustic
perception, although working together, can
compete with and affect each other, and this
effect is dependent on the frequency make-up
of each source. For example, the frequency
focus of the bassline, the transition from low
to high frequency content, and the type of
frequency gaps between the very low and midhigh frequencies will all influence the results.
Background
1. Griffin, M. J. (1990). Handbook of human vibration.
London ; San Diego, Calif., Academic Press.
2. Griffin, 1990; Verrillo, R. (1992). Vibration sensation in
humans. Music Perception 9(3): 281-302.
3. William Martens, personal correspondence.
4. Verrillo, 1992
5. Dalgarno, G. A vibroacoustic couch to improve
perception of music by deaf people and for general
therapeutic use. 6th International Conference on Music
Perception and Cognition. Aug 5th, 2000. Keele University
6. Altinsoy, E., Blauert, J., and Treier, C. (2001) InterModal Effects of Non-Simultaneous Stimulus Presentation,
Proceedings of the 17 th International Congress on
Acoustics. Rome, Italy
7. Daub, M., and Altinsoy, E. (2004). Audiotactile
simultaneity perception of whole-body vibrations
produced by musical presentations, in Proceedings of the
CFA/DAGA’04.
8. Martens, W. L. (2004). Perceived synchrony in a bimodal
display: optimal intermodal delay for coordinated auditory
and haptic reproduction. International conference on
auditory display, Sydney, Australia.
9. Martens, W. L. (2005). Tolerance for delay between
whole-body vibration and audio reproduction of musical
sound. Twelfth International Congress on Sound and
Vibration, Lisbon.
10. Martens, 2005.
11. Altinsoy, M. E. (2003). Effect of loudness on the haptic
force-feedback perception in virtual environments. Journal
of the Acoustical Society of America 114(4): 2330.
12. Hooper, J. (2002) Is VA therapy, music therapy?
Music Therapy Today (online), available at http://
musictherapyworld.net
13. Hooper, 2002
14. Dalgarno, 2000
15. Dalgarno, 2000
16. Martens, 2005
Page 19
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Phase 1
Collecting vibration sounds, composition basis in riddim
Feb 07 – April 07
Page 20
SURFACE RESONANCE
Phase 1 - Summary
Phase 1
Summary
This phase developed my understanding of how vibration sounds and may be captured, challenged
my approach to music-based vibration, and helped direct my focus to the making of ambient low
frequency sound and vibration.
I started to enhance, emulate and set up natural processes of low frequency sound in space. Field
recordings and music-based experiments with a large PA worked towards a composition that tested
some boundaries around referencing riddim and music-based vibration response.
My first project was to take field recordings of
music-based vibration around nightclubs.
Although the recordings contained good
examples of vibration, I found that the
overall sound was too obviously taken from a
nightclub/music context to be of use. When
listening back, the other musical elements were
very predominant over the vibration.
In response to this issue, I explored ways of
emulating this experience in a way that would
accentuate the characteristics of musical
vibration that were of most interest.
I generated content by looping a drum and
bass bassline, and applied processing to try to
filter and abstract the explicit musical aspects
of it. I then played the processed sound within
a space, through a large PA, and recorded the
effect this had on the space.
I based a composition around this. The
recordings were further processed, such as
through time stretching and layering, to
further abstract from the notable sense of
rhythmic pattern still underpinning the source
material. To further abstract the work, I also
incorporated ambient recordings of mechanical
and electrical low frequency sound.
Questions and research outcomes
I explored two of my principal research aims:
• 1.1 - Abstraction of “riddim” – basslines
moving from musical to environmental
• 1.2 - Low frequency sound activating spaces
- articulating building materials through
vibration
From field recordings, I had a better
understanding of how vibration sounds,
how it is created and relates to low frequency
stimulus, and how to record it. I realised its
complexity and the limitations and challenges
of trying to emulate it through software.
I compared the ‘live’ experience of being in
a space activated into vibration/resonance
by a large PA, to recordings of this space and
process. It was clear that much of the ‘live’
experience would never translate to recording
and reproduction. This was mainly because the
sensation and strong low frequency presence
in the space required a powerful audio system
with extended low frequency response. Also,
the overall sound came from a summation of
the many resonances and vibration responses
throughout the space, which would require
sophisticated recording techniques to capture,
and would likely be more interesting as a live
effect.
Page 21
SURFACE RESONANCE
Phase 1 - Summary
I considered this issue and that the other artists
I knew of working in the field were using
large PAs in performance to create vibration
[for example, Randy Yau and Scott Arford,
Zbigniew Karkowski].
I resolved that for my Masters project I
would explore alternative methods, suited to
loudspeaker reproduction, that would offer
listeners a sense of the vibration in spaces
without a reliance on big PA setups.
I considered that this would create a more
internalised and translatable experience, in
keeping with my focus on the perception of
vibration. It would also enable me to focus
on the range of ‘vibrations’ that could be
made from materials, rather than thinking of
vibration as an interaction of sound and space
in a live performance. This thinking directed
later research.
Using music-based recordings, I employed
many techniques to blur riddim but the
musical link/pattern remained. This presented
an ongoing challenge and made me consider
what relevant alternate approaches I could use
to heavy bass generation.
The use of more ambient material developed
my creative process and helped me explore the
idea that vibration potential is inherent within
materials, subject to low frequency stimulus.
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SURFACE RESONANCE
Phase 1
Table overview
Findings against principal research aims
Time/Work
Max/MSP,
trying to dissect
and reproduce
vibration sounds
Findings, focus,
key directions
Understanding
the physics of
surface resonance
Abstraction of
‘riddim’
Low frequency
sound activating
spaces
Tactile system as
an instrument
The dialogue
between hearing
and sensation
Consulting with
acousticians
Programming
building blocks
to emulate
vibration
Trying different
synthesis
approaches
Massive time
and technical
challenge
Field recordings
- vibrations from
nightclubs
Discover that
field recordings
give a too explicit,
musical reference
Recordings
intended to
be used in
composition
Realising the
sonic complexity
of resonant
surfaces, too
difficult to model
Aiming to
understand and
highlight the
nature of musical
vibration
Begin to
understand
the complexity
in recording
vibration
Field recordings,
atmospheric low
frequency sound
Furthering my
understanding
of the sound/
vibration
relationship and
characteristics
Finding locations
where low
frequency sound
was a dominant
characteristic
Trying to express
the natural
potential of
vibration to
occur, given the
right intensity of
stimulus
Page 23
SURFACE RESONANCE
Findings against principal research aims
Time/Work
Exciting vibration
in a space, large
PA
Findings, focus,
key directions
To create the
effect of musical
vibration without
the direct and
obvious sound of
a musical source
Considering
how reliant the
low frequency
sound effect is on
having a large
system – does
not translate on
recording
Processing
recordings to
disassociate
the bassline +
environment
Adding
atmospheric
low frequency
material
What can I
create without
reliance on a big
soundsystem?
Abstraction of
‘riddim’
Use of effects
to blur sense of
riddim
Effects to emulate
the natural
abstraction of LF
sound in a space
Focus and
understanding of
the bass stimulus
and vibration
‘tailing’ response
Low frequency
sound activating
spaces
Tactile system as
an instrument
The dialogue
between hearing
and sensation
Testing with
powerful
soundsystem to
achieve vibration
in a controlled
environment
Set up materials
to vibrate
Effects to smudge
the tonal and
timing emphasis
of the riddim
Shifting
Stepping further
away from riddim sequences to
further break the
sense of musical
pattern
Merging in
ambiences,
further shifting
the source
material
Concludes with work drawing on musical and environmental vibration. Research findings:
• I need to create sense of the vibration in spaces without reliance on big PA setups
• I gained a better understanding of how vibration sounds, is created and relates to low frequency stimulus, and how to
record
• Using music-based recordings, I employed many techniques to blur riddim but the musical link/pattern remains
• Use of more ambient material developed the creative process and helped explore the idea that vibration potential is
inherent within materials, subject to LF stimulus
Page 24
SURFACE RESONANCE
Phase 1.1 - Riddim
Phase 1
1.1 - Riddim
Phase 1 research on abstraction of riddim centred on controlled recordings of partly blurred/
abstracted basslines, and further work in the studio, to understand and address issues with using
such a music-based source.
Tests with a large soundsystem
To blur riddim and record the effect of sound
on a building, I developed music-based bass
material, and reproduced this through a large
(2 x 15” drivers) subwoofer, situated in a house.
The material started with looped basslines
from tracks that I had experienced as creating
powerful vibrations before. I focused on one
track in particular, Rwanda from Smith and
Mighty/More Rockers. I chose this early drum
and bass/dub crossover track because of its
low fundamental frequency, smooth
transitions between notes, and rich
tonal/upper harmonic content.
I combined this approach with reverberation,
which I employed thinking about the
experience of hearing music in warehouse
parties in industrial complexes, where the bass
sound becomes ‘fudged’ from reflecting against
building walls across a large space.
The use of these effects meant that, aside from
the core rhythmic repetition, the musical
elements were obscured. This enabled my aims
of finding a point where musical sound merged
into something that is registered as more
environmental.
I used a range of basic effects on this
track, selected because of their parallel
to the natural processes that low
frequency sound goes through in its
passage through a space.
I used a low pass filter that started
out very low (20Hz) and worked up
to 180Hz. This enabled a focus on the
lowest aspects of the music, and how
the different frequencies would affect a
space.
This filtering also paralleled the way that a
building acts as a natural attenuator of higher
frequencies, so that the lowest sounds (and the
effects of them on the building fabric) are all
that is heard outside the space.
Heartical Hi-Fi, reggae soundsystem
One of the black boxes (2x15”) was used
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SURFACE RESONANCE
Listening to the processed sound in the space
was deep, atmospheric and very submersive.
The overall sound, being based on music,
captured well the in-between musical/
environmental sense aimed for.
However, listening back to the recordings
on headphones and smaller loudspeakers
emphasised that this experience does not
translate without the powerful audio system.
For example, the rhythmic elements, while
smoothed/stretched by the interaction of loud
low frequency soundwaves in the space/body,
were more distinct and obvious when listening
back in an ‘ordinary’ context.
Despite this, both the actual and recorded
vibrations elucidated the sense of ‘building
response’ I was interested in, where particular
building elements responded to different
bass frequencies, and respondent vibrations
‘tailed’ the bass sound. The focused process of
contriving and recording a sound/vibration
relationship helped me better understand
the way spaces respond to vibration and the
transformation of riddim within a building.
Processing recordings to disassociate
the bassline + environment
I made a composition with the materials
gathered. I wanted to disassociate from
the obvious rhythmic elements of the PA
recordings, and make an acoustic piece that
evoked the sense of being in a bass/respondent
vibration space, without reliance on large
equipment to achieve this.
I started with three recordings taken from the
engineered soundsystem/vibration setup. The
phrasing of all of these was matched, being
taken from parallel/repeat processes of playing
Phase 1.1 - Riddim
back the low frequency sound track and
recording it in the space.
Once layered together, I processed the sound to
disassociate the recording from sounding like
a site recording, and being overtly rhythmic.
This included distortions, tone emphasis, and
changing levels and frequency filtering to
create interactions and progressions between
the tracks, bringing out and focusing on
particular tones and elements within a constant
piece.
I found that there was a remaining challenge
in that despite these changes, there was an
underlying semi-constant rhythmic element,
even if quite removed from the original source.
This appeared to be a potential distraction, or
too strong a focal point.
In response, I copied and time stretched
tracks to change their patterning, and further
experimented with volume interactions
between different timed tracks.
This had moderate success but questions
remained about the tension point created
by rhythm in the exploration of music/
environmental crossover.
While use of riddim posed this challenge, the
testing and composition process drew my focus
to the opportunities and areas of interest that
riddim offered. For example:
• how tone changes activate different materials
• how pulsed sound triggers a response from
vibrating materials in ways that drones do
not
• how my composition might evoke a musical
experience (and whether I wanted this).
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SURFACE RESONANCE
Phase 1.1 - Riddim
Adding atmospheric low frequency
material
At this point my thinking moved into how a
composition might evoke the ‘atmospheric’
as opposed to the ‘musical’, and how to draw
on the natural/environmental instances of
powerful low frequency sound to achieve this.
I took recordings around the Merri Creek
area. The area was chosen as urban activity
and technology presented sources of distinct
low frequency sound, against a relatively quiet
natural backdrop.
Locations where low frequency sound was a
dominant characteristic included an electrical
substation, under bridges that resonated
from the energy of vehicles, and under a train
station, capturing the arrival and departure of
trains.
These elements were incorporated within the
riddim-based composition.
I used a process of spectral convolution, which
is the multiplying of tone and amplitude
information between two tracks (with
the ambient recordings being the source,
multiplied with the vibration recordings from
the riddim experiments).
This resulted in a ghostly, tonal and resonant
effect, with spectral familiarity to the riddim
recordings.
This process enabled me to explore the idea
that all low frequency sound has a resonance
and vibration potential, and that subject to
the right respondent physical environment,
that any low frequency sound could create a
vibration response.
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SURFACE RESONANCE
Phase 1.2 - Materials
Phase 1
1.2 - Materials
Phase 1 findings on articulation of building materials came mainly through the initial field
recordings of vibrations from nightclubs, and the controlled testing to excite a building structure using
a large PA setup.
Nightclub recordings
My first approach to capturing bass-induced
vibration was to take recordings outside
nightclubs.
Background research included seeking advice
from online music communities and promoters
about venues with bass vibrations. After
surveying sound from eight potential sites, I
focused my recordings on two venues with the
most obvious vibration characteristics.
At the first venue, Brown Alley, the music
was dub/drum and bass. After investigating
the bathrooms, stairwells and service areas, I
took recordings from the windows and doors
of the venue. These were located near to the
subwoofers and offered clearly punctuated
mid-high frequency vibrations.
At the second venue I used rooftop access to a
nightclub with house music and recorded the
rattling of the metal sheeting and fixtures.
The recording process helped me better
understand the acoustic characteristics of
vibration.
When recording sound from a window or
door, the timbre would change dramatically
depending on where the microphone was
placed. The distance from the source made
a big difference, as the sound became less
‘aggressive’ or ‘sharp’ with distance.
This recording process also clarified how
complex vibration sound is. By using close
miking techniques, I could hear the way the
whole panel of a window or door vibrated in
different ways across its surface. The overall
sound was made up from the composite of
these vibrations interacting and supporting
each other.
This finding cast doubts about how effectively
I could ever synthesise vibrations through
Max/MSP, especially for more complex
objects such as panels. It did however suggest
that if I was able to take clean recordings of
vibration sound, and process these into very
small samples, they may be able to be used in
wavetable synthesis.
Setting up and recording vibration with
soundsystem
The testing of blurred basslines through the
large PA (see abstraction of riddim) also
involved experiments with how to best record
the resultant vibrations in the space. I tried
different placement distances, and using stereo
pairs vs close single miking. Close miking
seemed to offer the best result, as it picked up
the higher frequency sounds.
I also deliberately set up vibrations, by placing
glasses and cups next to each other. The sound
was generally not as interesting as wall/panel
vibrations, because the sound source was quite
obviously identifiable, and the vibrations didn’t
seem to ‘match’ to particular bass notes to the
same extent a wall resonance would.
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SURFACE RESONANCE
Phase 1.2 - Materials
Max/MSP work, emulating and
controlling vibration-like sound
During this time, I also attempted to build
a Max/MSP patch to emulate the sound
of vibrating materials. The idea was to use
generated or recorded low frequency sound,
and design sound software to ‘respond’ to such
sound when at an appropriate level/frequency
– generating a sympathetic vibration sound
in response, which could be controlled and
spatialisied.
The project included:
• consultation with a vibration acoustics
specialist, Jim Minnague, who explained
some of the physics of vibrating surfaces
• online research and seeking assistance from
Max/MSP forums, and acoustics groups
• trying to develop Max/MSP processes that
copied the ‘real-world’ physics of vibration
(for example, the modelling processes of
Perry Cook)
• searching for acoustic data of resonating
materials, such as their spectral makeup
• looking at how to generate content based
on such real world data, such as additive
synthesis from broken down samples of
vibration (application Spear)
• looking into wavetable synthesis as a means
of making sounds
• phase control of short sinusoidal samples
This understanding was the basis for the Max/
MSP programming, and also informed my later
approaches to composition, such as thinking
about thresholds in level above which vibration
or distortion would be activated.
I dropped this arduous programming process
after some months, as I realised that vibrating
material sounds were far too complex for
me to emulate, and recordings offered more
interesting source material that I might be able
to control in a way similar to the Max/MSP
intent.
This technical process helped me to understand
the physics of vibration. A material will
oscillate in sympathy with low frequency
sound, until its range of movement is
‘truncated’ by its physical boundaries (for
example, a window pane in a loose frame), at
which point it abruptly ‘clips’ and generates
non-periodic harmonics based on the original
activating frequency.
Page 29
SURFACE RESONANCE
Phase 2
First experiments with the table as an instrument
May 07 – July 07
Page 30
SURFACE RESONANCE
Phase 2 - Summary
Phase 2
Summary
This phase opened up a new approach to composition, using the vibration table as an acoustic compositional
tool.
I experimented with ‘playing’ the table by vibrating and dampening its surface. A subsequent presentation to
the Sound and Media Arts postgraduate students in the Sound Studio at RMIT helped solidify my directions,
installation and performance aims.
I found that the layers of processing used in the
Phase 1 composition had reduced the dynamics
and immediacy I sought from vibration sound.
To resolve this issue, I sent bass information
from the composition through a bass amplifier
and the vibration table, to excite small objects
into vibration. Recordings of the rattling
objects were added to the composition.
- composing for the body, and generating
sound
• 2.3 - Abstraction of “riddim” – basslines
moving from musical to environmental
• 2.4 - The dialogue between hearing and
sensation - felt and audible aspects affecting
awareness and perception of each other
This marked a shift from using vibrations
in recordings to generating and controlling
vibrations ‘in studio’, and opened up the type
of sounds I could use, with greater control and
isolation from other noise.
This phase concluded with a presentation and
discussion with the Sound and Media Arts
postgraduate students in the Sound Studio at
RMIT. It helped me think about the framework
in which I wanted to compose. I solidified my
interest in installation, with sensation, as a key
focus over performance. The main findings
follow.
I progressed to using the table itself as a
sounding device, with a range of tests around
using the table surface to generate audio, and
the way audio signals would behave when
applied through the table.
I started using drones and modulated bass
through the table, as a departure from bassline
riddim.
Overview of research outcomes
I explored all of my principal research aims:
• 2.1 - Low frequency sound activating spaces
- articulating building materials through
vibration
• 2.2 - Tactile system as an instrument
Using the loose MDF top of the table as a large
vibrating source offered a unique sense of
control and ‘playability’ for vibration sound.
I could use my body to change the pressures
across the surface to manipulate the vibration.
The large surface also offered a range of
approaches to miking, with the sound
character varying significantly depending on
microphone distance and placement across the
surface.
I found that vibrating surfaces were also
unpredictable in terms of the sound generated.
I was challenged by the way sound would
quickly transition from neutral to noisy
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SURFACE RESONANCE
Phase 2 - Summary
and discordant, and recognised I needed a
framework for generating sound that offered a
greater degree of control.
I began to understand the unique attributes
of sound as reproduced through the
vibration table – how upper harmonics
would dramatically reveal themselves with
incremental increases in volume, how
distortion of the electronic signal could
artificially emulate the way that vibrating
materials ‘distort’, and the frequency range best
suited the table.
I started using drones from my bass guitar as a
signal for the vibrating table. It diverted from
the riddim approach, and the organic source,
with rich harmonic content, had an interesting
combination of a deep drone, and high
frequency content that engaged the body. I
found very low frequency modulation (a shaky
sort of feedback) offered significant sensation
effects.
At the end of this phase I was motivated to
explore a greater range of vibrating materials,
as while the MDF was interesting in its
playability, it was not very interesting timbrally.
The sensory/feedback experience of playing
the table also refocused my aim to bring
sensation to an audience. Hence I decided on
an installation approach over performance.
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SURFACE RESONANCE
Phase 2
Table overview
Findings against principal research aims
Time/Work
Findings, focus,
key directions
Simulating
vibration from
composed
material, using
bass amp and the
vibration table
Shift from
using vibration
in recordings
to generating
material in the
studio
Abstraction of
‘riddim’
Develop idea of
the table as an
instrument
Understand
behaviour of
audio through the
table
Expression
through playing
the table
Tactile system as
an instrument
The dialogue
between hearing
and sensation
Working with
smaller material,
glass, bolts etc
Develop my
thinking on
the way I can
produce and
control vibration
sounds
Expand available
sounds and
options – a more
‘live’ sound
First experiments
with the table as a
sounding device
– larger scale
vibrating material
Low frequency
sound activating
spaces
Using a basic
three tone
riddim, aiming
for a simplified,
not expressly
musical sense of
rhythmic pattern
Using hand and
foot pressure
to dampen,
observing
how different
approaches
change the
character
of sound of
vibrating MDF
Gain a better
understanding of
how I can record
large surfaces,
microphone
placement
Drive to use
more materials,
to offer better
range of sounds
with expressive
range
First thoughts of
the table as an
instrument
Exploring the
sound of the
vibration table
itself: how tone
(increased
harmonics)
changes with
volume, best
frequency
range, and using
distortion to
emulate vibration
noise / harmonics
Basic synthesised
tones
Page 33
SURFACE RESONANCE
Findings against principal research aims
Time/Work
First time
generating
material intended
for the table
Presentation to
the postgraduate
group
Findings, focus,
key directions
Abstraction of
‘riddim’
Departure from
riddim. Wanting
smoothness of
vibration and
organic source,
with richer
harmonic content
Use of bass guitar
drones
Solidify intent to
have sensation/
installation focus
Recognising
unpredictability
in previous
drone/ feedback
experiments
Concept – method
of improvisation
Low frequency
sound activating
spaces
Vibration
transducer
feedback loop
to colour and
articulate the
sound into
modulation
Tactile system as
an instrument
The dialogue
between hearing
and sensation
Deep drone
+ harmonics
significant to
bodily sensation
Feedback with
shifting, organic
source offered
more playability
and expression
Method of
improvisation
– to have central
malleable content
with more
predictable range
to articulate
Group interest
in ‘live’
performance,
but I wanted
to capture the
sensation that I
had experienced
in composition/
testing
Research findings:
• I want to create sense of the vibration in spaces without reliance on big PA setups
• Recognise potential for playing the table and found bass guitar drones as suited to generating sensation and sound
• Focus on playability and expression around drones and modulation
• Understanding unpredictability when using the table this way and desire for structure to how I approach composition
• Playing the table refocused my aim to bring sensation into the audience experience
Page 34
SURFACE RESONANCE
Phase 2.1 - Materials
Phase 2
2.1 - Materials
Phase 2 research on articulating building materials involved causing objects to vibrate by placing them on the
table, and making sound from the loose MDF top of the table.
Simulating vibration from composed
material, using bass amp and vibration
table
Listening back to the preliminary composition
(see Phase 1), I found that the work was
flat, partly due to a lack of dynamism and
immediacy in its layered and processed sound.
Responding to this problem, I played the low
frequency components of the composition
through a bass amplifier and the vibration
table, on which I placed objects such as glasses
and coins. These rattled together, offering a
more ‘live’ and direct acoustic element, which
was recorded and added to the composition.
These steps motivated me to explore studiobased vibration sound, as a controllable way of
capturing the sense of object vibration.
First experiments with the table as a
sounding device – larger scale vibrating
material
After the small object works, I dismantled
the table top from its frame for maintenance.
As the MDF top was ‘floating’ on the frame,
undampened, it was predisposed to various
harmonic rattles when low frequency vibration
was sent through the steel understructure.
Interested in this effect, I tried a number of
sessions to see what basic elements changed the
harmonic and timbral response of the table.
Firstly, I walked on the surface and found that
by applying targeted pressure I could dampen
the vibrations, controlling and shaping the
vibration sound.
Next I explored how vibration results would
change with simple variations to the sonic
material sent through the table. I used a basic
three-tone rhythmic pattern with varying
amplitude, and found that increases in volume
would activate more of the upper harmonics in
the MDF, and that results would vary markedly
with small changes in level.
I extended from these tests by setting up a
passage of vibration, where a shifting bandpass
filter focused the signal of the rhythmic pattern
to a frequency range. The filter started at 20 Hz
and moved upward to 100 Hz over the course
of a few minutes, slowly opening up the upper
harmonics. Over three sessions, I experimented
how different approaches to surface pressure
would interact with this sequence.
Firstly, I left the table ‘neutral’, letting the
natural vibrations occur as I increased volume
and frequency range of the signal. While rattles
became more tonally complex with additional
high frequencies, they mainly sounded like
‘noise’ of an object than something with
deliberate tonal structure. The results were
more chaotic than expressive.
I next applied different approaches to hand
‘pressure’ on the table surface. I found that
deadening some vibration points (anti-nodes)
would tend to amplify others, as those parts
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SURFACE RESONANCE
of the surface were less constrained or had a
greater gap from the frame. This led to loosely
controllable localised vibration effects from the
interaction between frame and surface.
Finally, I experimented with applying ‘upwards
pressure and release.’ I lay underneath the
MDF and lifted sections of the perimeter, but
squeezed downwards at the same time from a
different location. I also used knives jammed
into the frame to change the points of contact
between table and frame.
Phase 2.1 - Materials
up some of the vibration points. While I mainly
used stereo microphones very close to the
centre of the table, I considered that in future
I would try multiple microphones, or multiple
recordings in different locations across the
surface.
This approach offered better control of the
vibration sounds, as there was a balance
between different vibration points, without
one area of the surface rattling too strongly. I
enjoyed articulating the sound by changing my
physical interaction.
Overall, the recorded results highlighted limits
to using the MDF table surface. The passages
didn’t offer much of a sense of tension and
release. The palette was clearly limited, as quiet
phases were not gentle or particularly subtle or
beautiful, and ‘noisy’ phases were not alarming,
aggressive or spectrally exciting. These sorts
of limitations suggested the need to work with
other materials.
However, the experiments helped me think
about the table on the whole as a sounding
device. The process and results suggested its
potential as a malleable instrument that one
could actively ‘play’ at a large scale, using body
pressure.
This testing was also instructive for
microphone technique. There wasn’t an obvious
best way to record the table, as while close
miking provided a more immediate sound than
placement away from the surface, it didn’t pick
Page 36
SURFACE RESONANCE
Phase 2.2 - Tactile instrument
Phase 2
2.2 - Tactile Instrument
Phase 2 experiments included composing for the body, and understanding the way the table reproduces sound.
By using different source materials I revealed the attributes of the table as a sounding device, and suggested the
way the body could engage with vibration through its surface.
First experiments with the table as a
sounding device – larger scale vibrating
material
The first tests (Phase 2.1) with putting a threetone rhythm through the table highlighted
differences between normal audio compared to
sound when reproduced through the table.
Most notably, small increases in signal level
led to dramatic increases in the level of upper
harmonics. High frequency elements would
jump out in steps, even when the increase in
signal level was smooth and incremental.
I also found that lower level signal would be
quite ‘noisy,’ with a lot of unwanted sound
generated even with a clean signal fed into the
table. At higher levels, the dominant vibration
tones would overtake this noise.
It appeared that these responses were a result of
both a) the vibration actuator itself, and how it
functioned as a quasi-loudspeaker, and b) the
physical structure of the table, being a heavy
metal and wooden frame, rather than a delicate
tool like a paper loudspeaker driver.
Understanding these limitations in dynamic
range and use of level helped my later
approaches to composition and testing, such as
in the work gutterglass (Phase 3).
came through at a lower level relative to deeper
tones, partly because they were dampened
by their passage though the table materials.
This meant that ordinarily harsh sound could
actually be quite pleasant when reproduced
through the table.
This was most evident with distortion from
digitally clipping the audio signal. This created
upper harmonics that if listened to as sound
though a loudspeaker or headphones would be
abrasive, but when played through the table,
worked well to generate extra tones that made
the sound more musical and harmonically rich.
This finding led to tests with using distortion
plugins as a means of generating harmonics for
a musical sound reproduced through the table.
I worked with harsh digital clipping in
particular, as it offered a sudden increase
in harmonics above a peak threshold. I was
interested in this behaviour as it paralleled the
way vibration sounds are made, when an object
exceeds a movement threshold and starts
to rattle. (See notes in Phase 1.2, Max/MSP
research).
I also applied digital and other distortion in
later tests such as the ‘March table project’
(Phase 5).
The table also showed a poor reproduction
of higher frequencies (above ~90Hz). These
Page 37
SURFACE RESONANCE
Phase 2.2 - Tactile instrument
First time generating material intended
for the table
Next I used a bass guitar to generate audio
signal source material for reproduction
through the table. See the section on
abstraction of riddim (Phase 2.3) for the
methods employed.
The harmonic structure from the guitar offered
a deep, strong sensation augmented by other
sensory information carried in the upper
harmonics. This tonal structure provided a
solid or ‘well rounded’ bodily engagement with
the table.
This connection of low frequency sensation to
high frequency sensation and hearing appeared
to relate well to what I had found in my music
sensation tests before the Masters program
(see background). In these early tests with a
vibration floor and loudspeakers, participants
responded well when the frequency content
of the bass in music was spread across the
vibration and acoustic elements. Where these
were not explicitly connected, with a large
frequency gap between the low sensation and
other elements, the vibration no longer added
to the overall experience and could become
disconcerting.
The use of the bass guitar also seemed to offer a
‘complete’ experience when physically engaging
with the table, such as playing with hands on
its surface or leaning against it. The upper
elements tingled the skin, relating to touch
with the hands and hand pressure, and the
lower elements provided more of a full body
engagement.
only in relation to finger vibration and skin
effects, such as people distinguishing buzzing
vs smooth vibrations depending on frequency.2
The experience of engaging with the table with
both the hands and the upper body highlighted
to me that while I came to the research with
an interest in deep, whole body sensation with
very low frequencies, it was important for me
to consider the role of the hands and finger
touch in engaging with the table surface. This
included the need for composing with both low
(30-50 Hz) and higher frequencies (80Hz+).
It also suggested that I may be able to offer
a more compete audience experience by
composing and installing for a reclining or
sitting experience, touching the table surface
with hands. I had initially envisaged a standing
experience consistent with the nightclub and
design research background I started from.
My later compositions (particularly undulation,
Phase 6) and eventual approach to presentation
(see presentation section) focused on a reclined
audience interaction.
1. Griffin, M. J. (1990). Handbook of human vibration.
London ; San Diego, Calif., Academic Press.
2. Verrillo, R. (1992). “Vibration sensation in humans.”
Music Perception 9(3): 281-302.
In previous research I had found that finger
and whole body vibration are assessed
separately in noise/engineering fields.1 I had
also found that some attributes of vibration
perception have been assessed primarily or
Page 38
SURFACE RESONANCE
Phase 2.3 - Riddim
Phase 2
2.3 - Riddim
During Phase 2, I progressed from source material with an explicit musical and rhythmic reference, to using
drones and modulations.
First experiments with table as a
sounding device – larger scale vibrating
material
During Phase 1, I struggled to abstract and
de-reference actual basslines from music. In
my tests with vibrating the table surface (Phase
2.1), I moved away from sampled music, and
used a basic, three-tone synthesised pattern
as source material. This approach helped me
to explore vibration-relevant attributes of
riddim without the direct musical link.
First time generating material intended
for the table
I set up a bass guitar with a small fan brushing
against its strings to create a drone, and fed
this signal into the table. This offered vibration
sounds, while avoiding the issues of music
reference and tone shifting. While not rhythmic,
it provided a gradual organic variability that I
couldn’t achieve with the previous material.
For example, I was able to explore the way
changing tones activated different resonances
in the table surface. Like with musical riddim
played through a loudspeaker system and
resonating a space, there was a definite
activation and release of parts of the vibrating
material, with each note carrying contrasting
tonal and harmonic structures.
However, while this approach managed to
avoid an overt reference to music, I found that
the result was mechanical, without room for
expression. I concluded that it was important for
me to continue exploring shifting tones, but that
I should use less rigid approaches to doing so.
This decision was partly because the switch
in tones was too obvious when assessed as
sensation. The experience failed to relate to my
previous experiences of riddim sensation, where
changes in tone and sensation effects were more
abstracted and smoothed over. Considering
my earlier testing, I knew this was partly due to
the less clear/accurate way that low frequency
sound travelled through a space, compared with
vibration sent directly to the body.
I shaped the drones by taping contact
microphones to the table and setting up a
feedback loop, which modulated the signal. I
then used a midi controller and hand pressure
on the table and microphone surfaces to
articulate the bass drone and feedback.
This provided pleasant deep drone sounds
that ventured into more chaotic modulation
feedback. Despite unpredictability and lack
of fine control, the results suggested the
possibilities of using slowly shifting patterns,
feedback and modulation to hint at the tonal
effects of riddim.
Page 39
SURFACE RESONANCE
Phase 2.3 - Riddim
1 = Bass guitar ‘played’, various
drones, plucks, strikes and detuning.
Signal from guitar fed into computer
2 = Audio signal from guitar fed from
computer, through amplifier, into the table
2a = the table generates vibration energy
(a ‘vibration reproduction’ of the
sudio signal)
= Vibration energy
from table
3 = a contact microphone used to pick
up the vibration on the surface. Creates
to the feedback loop, controlled seperately
4 = The “audio signals” are recorded onto
the computer, to be played back into
the table in future, used for composition
2a
1
3
2
Amplifier - drives
the table ʻvibration
acutatorʼ like a
loudspeaker
1, 2, 4
Computer multi channel
audio signal
outputs
Eliot Palmer - Surface Resonance - ADR
Overview of bass
guitar and tactile
feedback tests
Masters Sound Art
Page 40
SURFACE RESONANCE
Phase 2.4 - Presentation
Phase 2
2.4 - Presentation to group
At the end of Phase 2 I presented my progress to the Sound and Media Arts postgraduate students. Based on the
work with the loose table, group discussion focused on the performance potential of the system and a general
interest in the kind of sounds I was making. The discussions were particularly valuable to the research themes of
riddim, and the dialogue between hearing and sensation.
I presented a movie to the RMIT Sound and
Media Arts postgraduate students, showing the
experiments with tactile transducer feedback
(see riddim, Phase 2.3) and vibration with
small objects (see materials, Phase 2.1).
We discussed whether the research was
intended for performance or installation, as I
was not yet certain of the outcomes.
While talking about making the sounds, I
reflected that what was most interesting to
me was not the sounds made, but the tactile
experience of generating them. This discussion
helped me to resolve that the research would
focus on installation using the table, as this
was the only way to offer my exploration of
vibration sensation to an audience.
We also discussed how a vibration-based
approach might differ from works in the field
such as the low-frequency sound performances
of Randy Yau and Scott Arford. I highlighted
distinctions such as a vibration installation
offering an internalised sensation-based
experience, as opposed to performance using
sound to explore architecture and the role of
the body within a space.
The conversation also helped evolve my
approach to a ‘method of improvisation’ for
creating the audible elements of my work.
We discussed how making sound with
drones and feedback offered interactivity
and playability, but presented considerable
uncertainty in the way the table surface would
feedback.
The group queried how I might deal with this
unpredictability in composition and suggested
that I define simple and predictable parameters
to work within.
I brought this thinking to the my next
work gutterglass, where I used guitar drone
recordings as a stable reference point, and
techniques such as hand dampening and
releasing of the sound-making materials to
deviate from this.
Following the discussion I thought about what
I could do to further my research. I had already
explored ideas around:
• musical dissociation, and filtering /
distortion to blur between vibration and
tone
• parameters such as frequency range and
amplitude and how this affected table
sound/vibration
• riddim and its tension, potential and
limitations
• range of playability, (a sense of learning
instrumentation/techniques)
What was next? This thinking led to my work
under Phase 3.
Page 41
SURFACE RESONANCE
Phase 3
Playing the table, exploring sound-sensation interactions
August 07 – November 07
Page 42
SURFACE RESONANCE
Phase 3 - Summary
Phase 3
Summary
This phase was a substantial expansion on the ideas seeded through Phase 2. Through composition, I researched
the vibration sensation experience, asking questions about how sensation is perceived.
I broadened the range of materials placed on the table to generate sound, using large-scale building materials.
I responded to challenges in using the table as both a device for creating sound and as a vibration instrument.
I furthered my experiments with deep bass
guitar drones and tactile transducer feedback.
I focused on what would work as vibration
sensation, rather than as sound generated
through the table.
I recognised that there were inevitably some
audible sounds generated by the table, and
developed ambiences to work with these
sounds, to complete the vibro-acoustic
experience.
Next, I used the table to resonate building
materials such as windowpanes and sheet
metal. This provided a new palette of sounds
to work with the sensation experience. The
materials offered new approaches to playability
and expression when making vibration sound.
A first complete composition gutterglass (Phase
3.4) embodied this research. It helped me
understand how sensation, when combined
with sound, affects auditory perception, and
how vibration could work in a vibro-acoustic
narrative.
Overview of research outcomes
I explored the following principal research
aims:
• 3.1 - Tactile system as an instrument
- composing for the body, and generating
sound
• 3.2 - The dialogue between hearing and
sensation - felt and audible aspects affecting
awareness and perception of each other
• 3.3 - Low frequency sound activating spaces
- articulating building materials through
vibration
The research and composition process set
the building blocks for the rest of the masters
program, on how the senses interact, the
sorts of sounds I could create with building
materials, and the sort of vibration territory
that worked most naturally.
Page 43
SURFACE RESONANCE
Phase 3 - Summary
I addressed a unique compositional challenge
bought about from making vibro-acoustic
work.
I worked with vibration and sound, but
sometimes couldn’t experience these together.
I had to imagine the role one sense would play,
while working on the other element of the
work. I developed a software interface to make
this process more intuitive, and reflected on
how this challenge defined the approach I took
to composition.
This package of work formed a foundation for
the rest of my research, as it asked questions
around the role vibration might play within the
narrative of a vibro-acoustic work, and whether
the acoustic or vibration element should ‘lead’
the structuring of a composition.
Other outcomes were predominately about
strengthening and applying my earlier
findings in creation of a work, and focusing on
compositional approaches that seemed most
successful for both sensation and hearing.
Page 44
SURFACE RESONANCE
Phase 3
Table overview
Findings against principal research aims
Time/Work
Developing drone
material for the
table
Findings, focus,
key directions
Abstraction of
‘riddim’
Low frequency
sound activating
spaces
Providing
a stable,
controllable
platform for
improvisation
Starting with
the sensation
component
before sound
Highly detuned
bass providing
deep sensation
experience
First focus on
deep sensation
material
Developing
ambiences to
work with the
(ancillary)
sounds from the
sensation table
Vibration and
manipulation
of large scale
building materials
Develop ideas
of the table
as a sounding
instrument
Understanding
behaviour of
audio through the
table
Expression
through playing
the table
Developing
software
framework for
vibro-acoustic
composition
Enabling
channelling
of vibration,
ambiences and
recording
Vibration
transducer
feedback loop
Tactile system as
an instrument
The dialogue
between hearing
and sensation
Recognising
the need for
ambiences to
support the
ancillary sound
from the table
Tactile transducer
feedback to
articulate the
sensation
Drawing from
the initial
inspiration
and recording
processes
– vibration of
buildings
Wanting
vibration of
materials as
an edge of
augmentation of
other ambient
sound
New challenge
of composing
vibration
material sound to
go with vibration
sensation, when
both can’t be
experienced at
once
Improved
software to
make control of
the objects on
the table more
intuitive and
responsive
Microphone
experiments
Page 45
SURFACE RESONANCE
Findings against principal research aims
Time/Work
Composition
gutterglass
embodying
research
Findings, focus,
key directions
First thoughts/
application about
how sensation
can act within
the narrative of
a work
Applying idea
of ‘method of
improvisation’
Understanding
how sensation
affects perception
of sound
Developing
methods for
composing
sensation and
sound elements
Abstraction of
‘riddim’
Applying a
modulating,
deep drone
as a central,
predictable
element founding
the work
Low frequency
sound activating
spaces
Articulating
the openness
of the vibration
sound by hand
dampening,
this gesture
made against
other ambiences
already in place
Within the work
trying to cover
a whole range
of subtle to
discordant sound
from materials
Tactile system as
an instrument
A deep sensation
experience, not
aiming to engage
critical analysis of
the experience
The dialogue
between hearing
and sensation
Working process
for building
ambient and
vibrated acoustic
elements and
sensation
together
Based on a drone
that worked for
the body, but
when composing,
leading from
sound first,
vibration placed
around this
Developing a
narrative for
the role of the
vibration element
within sound
– to support,
enhance a sound,
then moving
to prominence
within the larger
piece
The experience of
sensation ‘mutes’
the sensitivity
to otherwise
potentially harsh
sound – sound
experience
highly altered by
sensation
Research provided the building blocks for the rest of the Masters program, on how the senses interact, the sorts of sounds I
could create with building materials, and the sort of vibration territory that worked most naturally.
Outcomes started to tie in most comprehensively to the four research aims.
Page 46
SURFACE RESONANCE
Phase 3.1 - Tactile instrument
Phase 3
3.1 - Tactile Instrument
I explored composition for the body, focusing on deep drone material that successfully engaged the body. Highly
detuned bass resting on the table for tactile feedback provided a balance between predictability and playability,
without chaotic feedback modulation.
Following the three-tone rhythm and tactile
feedback tests (Phase 2) and discussions with
the Sound and Media Arts postgraduate
students, I thought about:
• how to compose material for sensation, to
extend beyond my mostly sound-based
approach to date
• challenges such as unpredictability when
using tactile feedback
• issues of expression and playability with
tactile feedback
• my desire for a framework for improvisation
for making sound through the table
(as identified as an issue in Phase 2.2)
• scope to articulate and express beyond the
central sound, via additional layers of tactile
feedback and haptic interaction
• an ebb and flow to the sensation level
and frequency that alluded to musical
riddim. The additional modulation
through feedback also gave a sequencelike patterning, which provided a further
(abstracted) connection to riddim.
This provided a framework for the tactile
component of the work gutterglass, and was
also a springboard for the next steps of making
sound.
As a tangible project to address these issues,
I processed and arranged some crafted bass
drones for a sensation composition.
I highly detuned the bass guitar (very loose
strings) and placed it onto the table. The
signal from the guitar which was fed into the
table, creating a tactile feedback favouring the
resonant frequencies of the guitar strings. The
results provided:
• passages of very deep and sensorially
interesting vibration
• a way to focus on the sensation experience
rather than sound
• an organic variation in level, but within an
appropriately limited dynamic range that
minimised unwanted noise from the table
Page 47
SURFACE RESONANCE
Phase 3.1 - Tactile instrument
1 = Bass guitar ‘played’, various
drones, plucks, strikes and detuning.
Signal from guitar fed into computer
2 = Audio signal from guitar fed from
computer, through amplifier, into the table
2a = the table generates vibration energy
(a ‘vibration reproduction’ of the
audio signal)
4
2b = vibration ‘feedback loop’ generated
through the guitar, exciting different
responses from the guitar
3 = a contact microphone used to pick
up the vibration on the surface. Microphone
contributes to the feedback loop, controlled seperately
= Vibration energy
from the table
4 = the vibration through the floor is picked
up by a record needle. A feedback
loop explored seperately from the
guitar
2a
5 = The ‘audio signals’ are recorded onto
the computer, to be played back into
the table in future, used for composition
Other source material fed via computer
includes synthesiers, and processing
of the audio signal, including pitch
lowering, also executed in real time
1, 2b
3
2
Amplifier - drives
the table ʻvibration
acutatorʼ like a
loudspeaker
1, 2, 5
Computer multi channel
audio signal
outputs
Eliot Palmer - Surface Resonance - ADR
Overview of how
vibration is used in
sensation composition
Masters Sound Art
Page 48
SURFACE RESONANCE
Phase 3.2 - Hearing and sensation
Phase 3
3.2 - Hearing and Sensation
Phase 3 research on the dialogue between hearing and sensation included:
• addressing challenges composing for the two senses when they couldn’t be experienced together in the process
of making the work
• questioning how sensation could work as a narrative element within a composition
• finding that relaxing sensation affected perception of harsh sounds
• composing so that vibration suggested sound and sound suggested vibration, altering perception of each sense
Developing drone material for table
The bass guitar feedback drones (Phase 3.1)
provided a successful sensation experience.
However, for a person lying on the table to
experience the sensation, the table made
a significant amount of noise that was not
particularly interesting or engaging.
To complement the drone-based sensation
and this sound, I explored sound generated by
means other than the table.
From my background research and my own
tests (see background), I knew that listeners
could be distracted when sound and vibration
weren’t in time with each other.
Partly because of this, I focused on separating
the audio signal used for the vibration and
separately processing it to create accompanying
loudspeaker-reproduced material. Using the
same audio source, combined with the long
envelope nature of the drone material1, helped
to make timing less of an issue.
I made the sound spacious and ambient, and
accentuated harmonics that would connect
well to the tones heard through the floor.
This helped to create a summed experience.
It also avoided the issue of a large frequency
gap between the vibration and sound, which I
knew from my early music tests could create a
disconnect between these elements.
The work was largely done in Max/MSP, in a
patch I designed to allow for the processing of
multiple streams of sound from the original
drones, in a way that facilitated layering and
feedback.
Vibration and manipulation of large
scale building materials
Next I created vibration sound from large scale
building materials, and applied this together
with the computer processed ambiences (see
Phase 3.3 on the approach to crafting sound
from the materials).
These experiments were also firmly about the
interaction of the sound with sensation, and a
focus on making sounds that complemented
sensation as the central element to the work.
Gutterglass - role of vibration
Gutterglass developed from the above tests
with building body vibration and making
complementary sounds.
As I began to make and arrange the recordings
in a longer sequence, a new challenge emerged
on how to place sensation within a vibroacoustic composition.
While I aimed to develop the composition
around the vibration element, most of my
working process was on the interactions between
Page 49
SURFACE RESONANCE
Phase 3.2 - Hearing and sensation
Vibration and sound perception
the audible aspects. When mixing the computer
generated ambiences with the vibrating materials
recordings, it was too difficult to assess the
vibration at the same time.
Also, when creating the sound from vibrating
materials, I was unable to experience the
sensation component, and had to guess its
placement relative to the sound.
The sound ended up ‘crowding out’ my
perceptual faculties when structuring the work. I
wasn’t able to place the emphasis I wanted on the
sensation track, and it ended up being revisited
as a supporting element to the sound tracks.
The final composition had the vibration track
running alongside one part of the audible
arrangement (that of a discordant rattling
window). The vibration followed an arc of
increasing amplitude, and then decay. It moved
from supporting and enhancing the experience
of the sound, to prominence and demanding
more direct sensory attention.
This linked thematically to the approach taken
to each of the audible elements (see Phase
3.3), and helped me express the perceptual
continuum that vibration sits within.
The challenges around placing the vibration
within a mix also raised broader questions
about how effective and communicative
vibration could be. I asked:
Will vibration always be perceived as an
adjunct to sound, where sound is present?
Is it inevitably a ‘lesser sense’, in that it
doesn’t provide as much critical information
in a routine perceptual or evolutionary
capacity? To what extent can a composition
be based on and driven by sensation?...
The deep drone in gutterglass had a disengaging
or lulling quality. The sensation was almost a
sort of massage, encouraging shutting off of
critical thought or analysis of the sensation
and accompanying sound. This seemed to be
consistent with the kind of results offered by
vibro-acoustic therapy, which also tends to use
sensation drones.2
Gutterglass involved some fairly harsh sounds
from the vibrating building elements. The
relaxing or somnambulant properties of the
sensation seemed to dampen the listener’s
sensitivity to this. In my early music/vibration
tests, I found that vibration reduced sensitivity
to sound level. Gutterglass showed that this
might extend to perception of sound character
as well.
Some listeners found the sound in gutterglass
highly suggestive of vibration sensation, leading
them to believe there was sensation even when
not present. This worked with my deliberate
intent to only use the vibration within the
climatic phase of the composition. I continued
to take advantage of this psychoacoustic effect
in later compositions.
Intensity peaks in the sound also increased the
perceived vibration intensity for some listeners
and for myself when listening. The strength and
consistency of this effect was not entirely clear.
However, it appeared to conform to Altinsoy’s
findings on combined acoustic and tactile-force
stimulus, where increased sound level resulted
in a perceived increase in sensation feedback to
the hand3.
1. Martens, 2005
2. Hooper, 2002
3. Altinsoy, 2003
I explored these ideas in later compositions.
Page 50
SURFACE RESONANCE
Phase 3.3 - Materials
Phase 3
3.3 - Materials
Phase 3 provided substantial developments in the approach I took to making sound, as I moved to using largescale building materials and explored the range of sounds they could make.
Vibration and manipulation of large
scale building materials
After the work with vibration and processed
sound (see Phase 3.2), my focus moved back to
the vibration of objects.
In my Phase 2 testing composition I included
studio-based vibrations from small
objects (glasses, coins etc. on the table).
I went to a wrecker and picked dilapidated and
likely-to-rattle materials: two windowpanes
with much of the perimeter seals missing,
metal sheeting and tiles.
I experimented with placing these on the table
and creating sounds to go with the processed
sound textures.
This offered a ‘live’ sound that made
the composition more immediate and
connected it to the research interest in
building vibrations. However, like with
compositions by other artists using
small vibrating objects (for example,
Jeff Jerman, Untitled Sound Objects)
the properties of the vibration sound
didn’t sufficiently allude to the nature
of building vibration. For example,
what is experienced in a nightclub or
warehouse with loud dance music.
Conversely, my Phase 2 experience
in ‘playing’ the table MDF to create
sound offered a unique sense of control and
engagement with a large piece of construction
material, but presented quite one-dimensional
sound.
As a convergence of these experiments, it
struck me that now I had a large, manipulable
instrument that I could ‘play’, and that perhaps
it could be applied to large real-world building
materials placed on the table.
This offered something substantially new. I had
the large-scale tactile playability that I enjoyed
with just the loose table, but with greater sonic
range and freedom of expression through hand
dampening and arrangement of materials.
For example, I experimented with propping
the window panes at different angles to change
their resonances, layered the tiles on top of
each other to change the rattles, and used
finger pressure on key points on the glass and
guttering to change the profile of sounds.
Page 51
SURFACE RESONANCE
Phase 3.3 - Materials
In particular, I focused on the finger pressure
and release on the glass, across different points
on the surface, and how this could subtly
change the profile of the sound. Containing the
resonance through dampening also helped to
express the sound as an edge or augmentation
of the other computer processed textures,
rather than a continuous rattle.
The computer processed textures provided a
backdrop and reference point for making these
sounds. They also filled the sonic and timbral
gaps of the building material vibrations.
The building material sounds were on the
whole abrasive and bold in character. They
were mid-to-low frequency in nature, not
having any real high frequency content or
‘sizzle’. The computer processed textures
provided high frequency content and a smooth,
softer backdrop.
Developing software framework for
vibro-acoustic composition
I developed a multi-channel Max/MSP setup
to enable a more intuitive and responsive
approach to playing the table and objects. This
was essential to creating the work gutterglass.
In gutterglass, once building an initial sound
(from guttering), each aspect of the piece was
made by listening to the preceding ambient and
pre-recorded elements through headphones, as
well as the computer processed drone material.
The sounds captured by the microphones were
also fed to headphones so I could understand
their interaction (see illustration overleaf).
Page 52
SURFACE RESONANCE
Phase 3.3 - Materials
X
= Sound from
vibrating materials
= Vibration energy
from the table
(r)
(r)
1) The table used to vibrate
a material (e.g. window
pane) into resonance.
Materials also ʻplayedʼ/dampened
by hand and the sound recorded (r)
2) Recordings from 1)
listened to via headphones,
guiding next, and subsequent
recordings (r) made from
other materials (x) on the table
(r)
(r)
...
...
Audio output from
computer. Via amplifer
to drive table
Audio input to
computer. From
microphones,
recorded onto
hard disk
(r)
Computer multi channel
audio signal
outputs
Audio output to
headphones, of
previous recordings,
in addition to
ʻliveʼ sound
Eliot Palmer - Surface Resonance - ADR
“Live” sound
also monitored
through headphones
Final piece made from selection,
layering and processing of the
building material recordings.
Experienced via loudspeakers,
whilst engaging with the sensation
of the table. This sensation has the
same origins as the vibration used
to make the sonic material.
Overview of stages
for making a vibroacoustic work
Masters Sound Art
Page 53
SURFACE RESONANCE
Phase 3.3 - Materials
Gutterglass - approach to materials
Microphone findings
To make the audio parts of gutterglass, I set out
to cover the full sonic range available from the
materials, from quiet and ambient, to distorted,
rattly and discordant.
When making gutterglass, I experimented
with a range of microphone placements, using
microphone pairs, generally elevated away
from the vibrating surface.
I was guided by James Tenney’s Koan: Having
Never Written A Note For Percussion. Koan
sets up a gradual crescendo for a percussion
instrument, exploring how with repeated,
equally timed strikes of increasing intensity,
the instrument’s resonances and colour will
change.
This highlighted the complexity of the sounds,
and limitations to what I could capture without
very good microphones and precise placement.
Although sounds like vibrating glass were very
immediate and ‘sharp’ in person, it seemed
almost impossible to capture this, particularly
in the high frequencies.
The audio element of gutterglass combines
three building material recordings (guttering
and two different windows) that individually
follow a similar trajectory. All were activated
into vibration by the same pattern through the
table, which followed a gentle rise and decay
over several minutes. The final arrangement of
these recordings also traces the same general
pattern.
With two of the recordings, I used my finger
pressure and release to accentuate this rise
and decay, by gently reducing the amount of
dampening on the surface over the course of
the recording.
I found this was necessary as without some
control over the vibration, the materials could
make very dominant or harsh vibrations with
only very little vibration stimulus.
Page 54
SURFACE RESONANCE
Phase 4
Developing content for the table and the body
November 07 - October 08
Page 55
SURFACE RESONANCE
Phase 4 - Summary
Phase 4
Summary
This phase was principally about the vibration sensation experience.
I considered the constraints of the sensation medium and how to deliver within these. I focused on the basic
elements that made up different experiences of sensation, directing my compositions to sensation without
complementary or leading sound.
I developed a second composition that
combined sensation and hearing, and
attempted to provide more space for
improvisation and gesture when making
sensation. This presented new challenges
around how different frequencies and
intensities of low frequency signals would
interact when presented as sensation.
When interacting multiple vibration
tones, I experienced phase interference /
cancellation issues (modulations and collapse
of the vibration signal). These suggested tight
limitations on building sensation composition.
I developed further experiments and a working
methodology from this finding. A composition
made for sensation without sound helped to
solidify and apply my findings.
The work also helped me to set logical
boundaries when placing compositions
within the spectrum between symbiotic or
‘contrapuntal’ interaction between the acoustic
and tactile elements.
Overview of research outcomes
This period explored all of my principal
research aims:
• 4.1 - Low frequency sound activating spaces
- articulating building materials through
vibration
• 4.2 - The dialogue between hearing and
sensation - felt and audible aspects affecting
awareness and perception of each other
• 4.3 - Tactile system as an instrument
- composing for the body, and generating
sound
• 4.4 - Abstraction of “riddim” – basslines
moving from musical to environmental
A main finding was that texture was integral
to how vibration engages with the body, over
tone, frequency or other aspects of timbre.
I also identified and began to address
conceptual challenges about using vibration as
a medium to express and communicate.
At the end of this phase I found a comfortable
and successful range of approaches to sensation
composition, based on a more developed
understanding of sensation perception.
Page 56
SURFACE RESONANCE
Phase 4
Table overview
Findings against principal research aims
Time/Work
Revisiting
sensation from
riddim
Findings, focus,
key directions
To better explore
riddim from
a sensation
perspective
Referencing
again the real
world example
of sensation and
vibration
Composition
– “Sines 121
Hz” exploring
sensation
construction
Aiming for more
improvisational,
expressive
approach to
vibration and
sound generation
Building layers
of low frequency
tones
Reflecting on
fundamental
limitations and
boundaries
to vibration
experience
Abstraction of
‘riddim’
Low frequency
sound activating
spaces
Deep bassline
loops, dubstep,
Scorn etc.
Tactile system as
an instrument
The dialogue
between hearing
and sensation
Approach
and aesthetic
judgements
founded on the
experience for
the body
Fudging riddim
through delays,
reverbs tuned for
sensation
However, cannot
escape the sense
of musical
structure
Trying to push
the properties of
glass – aiming for
brighter, more
brittle sound
Exploring this
also through mic
technique
Acknowledging
limitations in the
material
Issues of phase
interference as
vibration signal
Building subtle
lower frequency
components to
support other
tones
Emerging
understanding
– interaction
of tones as
vibration needs
careful structure
Testing logic of
complementary
vibration and
sound
Trying for
counterpoint,
different
narrative between
sensation and
acoustic events
Recognising that
the vibration
medium is very
‘coarse’, and
simplicity is
necessary
Questioning
– how expressive
can the medium
be? What can
I communicate
and how should I
approach this?
Page 57
SURFACE RESONANCE
Findings against principal research aims
Time/Work
Content creation
for sensation,
without sonic
relationships
Findings, focus,
key directions
Low frequency
sound activating
spaces
Tactile system as
an instrument
Focusing on
frequencies, with
sensation ‘sweet
spots’ that engage
the body
Methodical
approach to
generating tones,
phase shifting
effects
Developing
material
according
to stutters,
modulations,
drones
Challenges: body
picks up on
very small shifts
in frequency,
tone generation
instructive but
mechanical
Revelation
– TEXTURE
integral to
how vibration
engages with the
body, over tone,
frequency or other
aspects of timbre
Work “bass
feedback July 08”
– based solely on
tactile experience
Abstraction of
‘riddim’
Using modulation
with stutters,
plosions, jolts to
engage the tactile
sense
The dialogue
between hearing
and sensation
Turntable
pickup feedback,
expressed with
the body
Extreme pitch
shifting to focus
on engaging
sensations
Use
underpinning
very low
frequencies
Focus away from
comfortable
drones to
something
encouraging
thought on
sensation
Breaking down elements of sensation opened up my understanding and work through concerns with the limitations of the
medium.
Page 58
SURFACE RESONANCE
Phase 4.1 - Materials
Phase 4
4.1 - Materials
My Phase 4 findings on articulating building materials were mainly about making my approach to soundcreation more expressive and improvised.
Testing through composition also helped explore the resonant ‘sweet spot’ of materials and the timbral range of
vibrating glass/windows and metal.
Composition ‘Sines 121 Hz’ exploring
sensation construction
I made this testing composition at the same
time as gutterglass.
I also tried to reveal the more brittle and bright
properties of the glass, to suit the dramatic
approach in the work and to expand the tonal
range I could work with.
I placed old corrugated iron on the table and
applied a 121 Hz sine tone vibration to it, tuned
to achieve a strongest resonance from the iron.
I used a range of near and far microphone
techniques, and applied very intense vibration
with only loose dampening of the materials,
to emphasise higher frequencies and harsher
tones.
I experimented with changing the level
of vibration and with hand dampening,
to further articulate its sonic range. I also
applied harmonically related lower tones, fed
underneath the 121Hz tone, to achieve more
‘wobble’ and ‘flutter’ in the vibration signal.
However, it emerged through the recording
process that the presence and intensity heard
in the room was still not being well captured,
even with these approaches.
When activating and dampening materials to
craft the sound, I aimed to provide a sense of
‘containment’ to the vibration sound. This was
to suggest that there is this vibration potential
in any material, which can be revealed with
sufficient low frequency stimulation.
Whilst listening back to an iron sheet
recording, I followed the same steps with a
window pane, to work with the prerecorded
track.
When making the work, I focused on ‘bold’
interactions between each track, to provide
more space for free gesture and dynamic
response, compared to the more carefully
structured gutterglass.
It also became apparent that the glass itself
didn’t provide much high frequency energy
(i.e. above 14kHz) and most of the energy
was under 2KHz. This appeared to be due
to its resonant properties and the lower
frequency signal driving it. These limitations
in expression and sonic presence led me
to consider greater use of digital signal
processing.
Later works (see Phase 5, ‘March table project’)
applied effects to amplify or reproduce the
vibration characteristics that were most
striking in a natural / real-world context.
Page 59
SURFACE RESONANCE
Phase 4.2 - Hearing and sensation
Phase 4
4.2 - Hearing and Sensation
Phase 4 tests helped me to set logical boundaries when placing compositions within the spectrum between
symbiotic or ‘contrapuntal’ interaction between the auditory and tactile senses.
Composition ‘Sines 121 Hz’
In gutterglass, I set up a logical and comfortable
interaction between the tactile and acoustic
elements, where the sensation matched the
sound in timing and intensity.
Sines 121 Hz’s arrangement was less
synchronised. More intense passages of
vibration roughly followed the timing of
intense sounds, but with occasional and
variable timing differences such as a slight
delay in onset. I also set up variations in the
form and intensity of vibration that did not
directly respond to sound.
This approach was taken to:
• ensure I didn’t limit myself to what was
initially appealing, but obvious
• cover less explored territory. I understood
that vibro-acoustic therapy tended to use
aligned sensation and sound to provide
a relaxing effect.1 Interfering with this
alignment offered potential for different
types of experience.
• respond to my own perception of vibration.
With extended listening, I became
‘densensitised’ to the overall relaxation/
disengagement effect of the vibration
experience, and started to focus on the
subtleties of presentation and sound/
vibration interaction
• test how participants would relate to the
work when the senses were not matching
each other all the time
• allow me to follow passages of vibration that
were effective for the body, without being
bound to how this matched the sound (see
Phase 4.3)
Consistent with the rest of the composition, the
counterpoint between hearing and sensation
was coarse and dramatic.
Feedback from my supervisor and others
suggested that the disconnect between the
senses was too much. People commented that
they expected a synchronised relationship
between the elements. By going against this,
the piece felt ‘illogical’ and distracting.
The comments suggested that future tests on
divergent sound and vibration would need to
be carefully framed. I continued to explore
this theme in later works, but with more
subtle timing offsets, and limited to particular
patterns of vibration (see undulation Phase 6).
1. Hooper, 2002
Page 60
SURFACE RESONANCE
Phase 4.3 - Tactile instrument
Phase 4
4.3 - Tactile Instrument
During Phase 4, I substantially developed my understanding of how to craft sensation elements, considering the
specific way that low frequencies would behave as sensation through a tactile transducer.
I also considered the limitations of the medium, in terms of the content or experience I could communicate or
express. I was concerned about the lack of acuteness of the tactile sense, compared to hearing.
Working from this, I built up sensation composition from very basic elements. This improved my understanding
of how to compose for sensation.
A key finding was that texture is integral to how vibration engages with the body, more than tone, frequency or
other aspects of timbre.
Composition ‘Sines 121 Hz’ exploring
sensation construction
I started the sensation element of this work
with a 121 Hz sine tone, fed through the table
to loosely follow the envelope of a segment of
the acoustic track (see Phase 4.2 on the sound/
sensation dialogue).
This frequency was physically engaging but
also forceful for the head when lying on the
table. The vibrations appeared to travel very
efficiently through the skull, with effects on
vision.
I focused on how I could make more engaging
and comfortable sensation effects, based
around the 121 Hz tone and a loose correlation
with the sound component.
I tested a selection of harmonically related
undertones. These expanded the range of
sensations I could present, including more
whole-body sensation. They also partly
neutralised the strong head sensations from the
121 Hz tone.
I applied these deeper tones to accentuate,
through sensation, the more dramatic
moments in the sound. As with the creation
of sounds, I focused on loose gesture and
improvised expression.
However, I found that I couldn’t just ‘push’
energy into the table by driving different tones.
The different vibration waves strongly phase
cancelled and modulated each other.
The resulting sensations sometimes totally
diverged from what I was hoping to express
at that moment. The interactions were
unpredictable, varying significantly with the
different levels of tones and slight frequency
differences.
There did not appear to be the same latitude for
phase interference as there is with loudspeakers
and sound, as the vibrations were focused on
a single point source and surface area, unlike
soundwaves varying across a listening room/
space.
Consequently, I decided to focus on building
up sensation tones more slowly, through
repeated listening and track automation,
rather than through real time gestures and
improvisation.
Page 61
SURFACE RESONANCE
Another finding was that very low-level, lowfrequency tones could be used underneath an
existing tone, and that these could alter the
feel of the tone, adding a deeper texture to the
sensation without abrupt phase interference.
Both of these findings were applied in my
approach to later works.
Reflecting on fundamental limitations
of and boundaries to the vibration
experience
Phase 4.3 - Tactile instrument
in order to be clear.
My experiences suggested that fundamentally,
our perception of vibration is one-dimensional.
Vibration appeared not to carry the same
capacity for emotional/intellectual significance
as sound.
These technical concerns led me to consider
broader issues about what could be ‘expressed’
through vibration without a supporting or
leading sound. I asked:
Making gutterglass and sines 121 Hz
highlighted how coarse the vibration medium
was compared to sound.
Can vibration be expressive or emotionally
communicative? Does it need to accompany
sound to carry such intent?
I had to deal with the limited dynamic range
of sensation, because the vibration actuator
didn’t work well at low levels, and because of
limited perceptual sensitivity/range compared
to sound.
What do these limitations mean for my
research aim of exploring the medium of
vibration? For the vibration to be expressive/
communicative does it need to form part of
sound? To date, my tests with vibration by
itself didn’t seem to provide content that
made aesthetic sense to the listener...
The challenges when making sines 121 Hz also
suggested that vibrations needed to be simple
Page 62
SURFACE RESONANCE
Phase 4.3 - Tactile instrument
Content creation for sensation, without
sonic relationships
My concerns about the limitations of vibration
for communication and expression led to a
series of tests. I focused on what is engaging
and interesting to the body, without need for
supporting sound.
I started by testing which frequencies activated
the table or the body in interesting ways. I
swept sine and saw tones through the table (15
to 150 Hz). I noted the tones that provided a
strong sensation effect (for example, 23 Hz,
25.5 hz).
While this material was simplistic and
mechanical, it was useful to understand that
single, simple tones could be interesting as
vibration, and that each tone had a distinct
sensation character. In later works, I often
drew from this bank of tones, to support other
the studio space and back to the turntable.
A hit to the vibration table could set the
feedback cycle off.
I made an interesting range of vibration states
by standing, lying, and pushing on the table in
different ways and locations across its surface.
Depending on how the table was grounded to
the floorboards, I could make modulations,
stutters or drones from the feedback.
Similar to my early tests with the loose table
top (see Phase 2), it was very engaging to
actively play the table with my body.
I edited the turntable feedback recording
into segments, based on the pattern of the
vibration, such as how the vibration ‘fluttered’
or ‘throbbed.’
Parallelling the earlier sine-tone
tests, I pitch shifted these segments
until I found a ‘sweet spot’
where they were most physically
engaging.
This experiment significantly
developed my understanding of
sensation.
vibration elements in the composition.
Next I experimented with turntable feedback.
I put a turntable needle on the outer rim of a
still record. The very low frequency resonance
of the turntable pickup/tonearm became an
amplified electronic signal. This signal was sent
to the vibration table.
The vibrations through the table were sent
from its frame and legs, into the floorboards in
My approach to the vibration
sensations was about their texture,
rather than tone or timbre. I thought about
characteristics such as roughness or shakiness,
rather than pitch or harmonics.
Often, I drew comparisons to real world
experiences of vibration texture, such as
driving a car over the edgeline of a road, or
touching a panel on a motor casing.
This development was significant to how I
approached all future sensation compositions.
Page 63
SURFACE RESONANCE
Phase 4.3 - Tactile instrument
1 = Bass guitar ‘played’, various
drones, plucks, strikes and detuning.
Signal from guitar fed into computer
2 = Audio signal from guitar fed from
computer, through amplifier, into the table
2a = the table generates vibration energy
(a ‘vibration reproduction’ of the
audio signal)
4
2b = vibration ‘feedback loop’ generated
through the guitar, exciting different
responses from the guitar
3 = a contact microphone used to pick
up the vibration on the surface. Microphone
contributes to the feedback loop, controlled seperately
= Vibration energy
from the table
4 = the vibration through the floor is picked
up by a record needle. A feedback
loop explored seperately from the
guitar
2a
5 = The ‘audio signals’ are recorded onto
the computer, to be played back into
the table in future, used for composition
Other source material fed via computer
includes synthesiers, and processing
of the audio signal, including pitch
lowering, also executed in real time
1, 2b
3
2
Amplifier - drives
the table ʻvibration
acutatorʼ like a
loudspeaker
1, 2, 5
Computer multi channel
audio signal
outputs
Overview of how
vibration is used in
sensation composition
Page 64
Eliot Palmer - Surface Resonance - ADR
Masters Sound Art
SURFACE RESONANCE
Phase 4.3 - Tactile instrument
Work “bass feedback July 08” – based
solely on tactile experience
Between July and October 2008 I developed
a work focused only on sensation, without an
audio component.
This incorporated elements and findings from:
• the sines 121Hz work on constructing
vibration from underpinning deep tones
• earlier experiments with bass guitar feedback
• returning to other (non-drone/feedback)
results from the guitar tests, and focusing on
plucked strings and impulsive elements
• the turntable feedback
• using substantial detuning/pitch shifting to
find sensation ‘sweetspots’
• the shortcomings and successes of the
concurrently conducted audio-tactile
composition (see Phase 5), where I tried
to avoid working with just drones and
modulations
The composition was evocative of faulty
equipment or electrical shorting. It
incorporated short, jolting bass guitar plucks,
with deep sines interacting at low levels, and a
slightly ebbing passage.
The work was deliberately not comfortable,
but stimulating and focus-grabbing from just a
sensation perspective.
Page 65
SURFACE RESONANCE
Phase 4.4 - Riddim
Phase 4
4.4 - Riddim
During Phase 4, I experimented further with abstracting music basslines.
Dedicated work on abstracted riddim as
a sensation
The following research was separate from the
sines work and sensation-only composition.
I had previously tried a range of techniques
to blur and obfuscate the sound of music
basslines, to make work that subtly referenced
riddim without an obvious musical link. I
found that this was difficult to achieve and that
any residual rhythm would grab a listener’s
attention.
During Phase 4, I applied similar techniques
to blur the vibration from music basslines, as
represented through the vibration table.
I sampled and edited small bassline loops,
primarily from dubstep tracks with a suitable
frequency concentration at below 60Hz. I used
reverbs and delays to smooth the sample into a
more constant sensation.
body that shifted with different notes. Even
when smoothed out and more gradual, this
transition between notes seemed important to
maintain.
This finding guided later thinking on how
undulating low frequencies could create an
effect similar to riddim.
I was also reminded that the shifting tones
offered different acoustic effects to those from
drone vibration.
Materials in the studio and parts the table
surface were activated by specific notes. The
effect was similar to the ‘real world’ way that
heard vibration in building materials can come
from passing low frequency sounds, like a form
of ‘delay’ from the room, triggered for a short
moment in response to a bass note.
This reaffirmed the importance of continuing
to consider riddim-based vibration, despite the
recent successes of drone-based material.
It was difficult to avoid the overt musical
reference in the vibrations. However, with
some material and processes, I was able to set
up a softer undulation between notes, without
strong rhythmic punctuation.
This seemed to capture an essence of the
basslines in a new way, and highlighted the
continued relevance in drawing from riddim.
Unlike the results from the recently applied
drone material, this music-based approach
provided a sense of ‘grip’ and ‘release’ to the
Page 66
SURFACE RESONANCE
Phase 4.4 - Riddim
Page 67
SURFACE RESONANCE
Phase 5
New approaches to sensory interaction and vibration sound
March 08 - July 08
Page 68
SURFACE RESONANCE
Phase 5 - Summary
Phase 5
Summary
During this phase I resolved some of the challenges raised during earlier compositions, primarily concerning the
dialogue between the senses.
I investigated the ways perceptual focus can shift depending on the way sound and sensation are presented. This
included developing my process for composing sound with sensation. I also expanded the sonic palette I was
working with from vibrating materials.
I moved outside the compositional comfort zone established in earlier work.
I made a new work ‘March table project’ with
different vibrating materials, greater layering
of sounds, and different vibration effects. I
approached the compositional narrative in a
new way, leading from vibration rather than
sound.
I presented the acoustic component of the
work to Berlin based sound curator Elke
Moltrecht. Feedback from her and others
highlighted the shortcomings and lessons from
the composition, and validated my intended
approach for installing vibration with sound.
Overview of research outcomes
This period explored the following principal
research aims:
• 5.1 - The dialogue between hearing and
sensation - felt and audible aspects affecting
awareness and perception of each other
• 5.2 - Low frequency sound activating spaces
- articulating building materials through
vibration
The main development was in my
understanding of how perception shifts focus
depending on the makeup of the sound and
sensation elements in a composition.
I started by focusing on engaging sensation
components/phrases. However, when I
introduced sound into the composition it
‘sidelined’ the amount of engagement or
focus a listener could have on the sensation
experience. The audible sense took primacy,
even where the content was meant to support
the sensation experience.
This had an important bearing on my approach
to structuring compositions. It was also
challenging when moving back and forward
from sensation generation to audible vibration
generation, as these both couldn’t always be
experienced at once.
I thought about the narrative arc that I
wanted to employ. With gutterglass, I found
a comfortable area based on drones and
closely aligned, simple passages of sound and
sensation. In the ‘March table project’, I aimed
for smaller phrases of sensation such as stutters
and pulses, and more complex sound/sensation
interactions. I tried to avoid staying within
the comfort zone of the earlier work, and to
establish a greater the range of inter-sensory
experiences.
I also worked with new sound-making
materials including wires and metal sheeting,
made harsh and discordant vibration sounds,
and layered many sonic elements together.
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SURFACE RESONANCE
Phase 5 - Summary
I found that I needed to limit the complexity
and layering of sounds given their
(in)harmonic makeup, and that I didn’t
need to reach full discordant vibration from
materials. I also improved my understanding of
microphone technique and eq’ing.
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SURFACE RESONANCE
Phase 5
Table overview
Findings against principal research aims
Time/Work
Findings, focus,
key directions
Element 1 of
composition
‘March table
project’
– building from
vibration
Structuring
a longer
composition
around passages
of engaging
vibration
Moving away
from comfort
zone, avoiding
easier approach of
lulling drones
Element 2
– building layers
of sound
Tension develops
– vibration
becomes
subordinate
to sound,
and vibration
narrative
gets lost with
accompanying
sound
Pushing my
understanding
of inter-sensory
dialogue
Abstraction of
‘riddim’
Low frequency
sound activating
spaces
Tactile system as
an instrument
Mixture of
vibration effects,
broken up and
not following
smooth drone
type passage,
aiming for
more complex
compositional
arc
The dialogue
between hearing
and sensation
Aim to have
sound build
on vibration
experience,
rather than
vibration
enhancing
the acoustic
information
Using material
from range of
previous tests,
guitar feedback,
turntable
feedback, plucks,
stutters, sines
– all based on
engaging texture
Building layers
of sound, flattens
the perceived
timing, decays,
and articulation
of the vibration
Rearrange to
enable sound
lead
Build other
passages without
vibration
element, or
more subtle
underpinning
vibration
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SURFACE RESONANCE
Findings against principal research aims
Time/Work
Element 3
– expanding
range of materials
Findings, focus,
key directions
Abstraction of
‘riddim’
Low frequency
sound activating
spaces
Opening up
frequency range,
colour of sounds,
mic technique
Using greater
range of materials
– wires, glass
objects on metal
Aiming for harsh
and subtle sounds
Close miking
technique
Working on
intersection of
many different
vibrating
materials
recordings
Many layers of
sound, aiming
for greater
complexity
Tactile system as
an instrument
The dialogue
between hearing
and sensation
Inharmonic
clashes, try to
craft around
using more eq, fx
Excellent research process, but end result overlaboured and not successful artistically. Pushed from my comfort zone in
how to structure work, tested boundaries in how the senses interacted, approached the compositional narrative in a new
way, and learnt much about selecting, miking and arranging materials.
Most useful were understanding limitations which guided later work, on limiting the complexity of sounds given their
(in)harmonic makeup, on not needing to reach full discordant vibration from materials, on the advantages in drones,
modulations, on not becoming lost in tweaking recordings. Also significant gains in my understanding of microphone
technique and eq’ing.
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SURFACE RESONANCE
Phase 5.1 - Hearing and sensation
Phase 5
5.1 - Hearing and Sensation
During Phase 5 I concentrated on the way perception focuses on sound over sensation, and what this means for
composition.
In gutterglass, I created a structure largely
suggested by sound, and interwove the
vibration into this.
For the ‘March table project’, I started from
the building blocks of what makes interesting
sensation. I used material from the earlier
experiments (sines, saws, turntable and bass
guitar feedback), and arranged these into a
passage that by itself was physically engaging
and possessed a sense of internal logic.
I avoided using one lulling oscillation or drone,
and applied a range of rattles, shakes, stutters,
explosions, and undulations, based on textures
that were interesting to the body.
In response, I edited and rearranged the
material, to maintain, on a micro level, the
sensations that worked, but create a macro
structure that was led by the sound.
From this rearrangement, I created and
inserted other passages of sound to make the
macro structure work better. Not all of these
contained a vibration element in support.
These steps developed my understanding of
the vibration/sound dialogue and the overall
possible role of vibration within a composition’s
structure/progression.
I built the sound around this by placing
materials on the table and causing them to
resonate in response to the same vibration
passage. I made multiple recordings, and then
listened to layerings of these with the sensation.
Soon a challenging friction developed, as what
made sense for the body became subordinate
to the heard content. Vibration structures that
worked in isolation lost their internal logic
when the sound was present, and the vibration
was no longer as engaging.
Also, the decays, timing and articulation of the
sounds wasn’t ideal, because they were made
according to the vibration compositional arc.
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SURFACE RESONANCE
Phase 5.2 - Materials
Phase 5
5.2 - Materials
During Phase 5 I explored new materials and miking techniques, to expand the tonal range and complexity I
could employ.
My previous works involved an
interaction between one or two different
recorded materials (such as windows
and sheet metal) plus other ambiences
or effects.
In the ‘March table project’ I focused
on new sounds and textures that
occupied a higher frequency register. I
also used smaller elements and features
in addition to the larger vibrating
materials. These included wires on
metal, thin aluminium, and glasses and
bolts on metal and glass.
I applied less hand dampening and
releasing than with earlier works,
focusing instead on the miking approach.
I used very close miking techniques
(a few mm away from the surface)
to highlight particular buzzes and
resonances from the materials that were
specific to points on the surface. I also
recorded at locations close to the surface
where multiple strong vibration points
(anti-nodes) could be heard interacting.
To make a more complex work, I made
many recordings, with up to 15-20 to
draw from for any one passage.
This layering process presented a new
challenge. The resonating materials
were largely inharmonic, and the
structures of their overtones don’t follow
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SURFACE RESONANCE
Phase 5.2 - Materials
neat or even structures. Consequently,
with layering, it was difficult to find
overlaps that married well, particularly
when using different types of materials
together.
I spent a considerable amount of time
eq’ing and applying effects to narrow
or strip down to the essence of each
sampled sound, to maximise the
potential for using sounds alongside
each other.
While the end result was over-processed
and dense, these steps helped me to
understand the nature of vibration
sounds and how to best reveal and interrelate them.
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SURFACE RESONANCE
Phase 6
Riddim exploration to a focal point, settling expressive range
August - November 08
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SURFACE RESONANCE
Phase 6 - Summary
Phase 6
Summary
This phase marks a conclusive point in my research. Through research and a composition, I found an effective
domain for creating sound and vibration.
I addressed questions about sound from building materials, the abstraction of riddim, and the dialogue between
the senses.
The final approaches represent a:
• settling of the palette I wish to work from, within the context of a defined field
• more developed approach to sound-sensation dialogue
• comprehensive understanding of how to use the table as an instrument
During this phase I applied more advanced
approaches to vibration generation, including
collaboration, real time pitch shifting and
processing, and microphonic and tactile
feedback to enable deep, textured and
predictably manipulable vibrations.
I also worked with new materials, including
an oil drum, as well as new microphone
techniques. The composition undulation
brought together the research findings and
practice.
This period explored the following principal
research aims:
• 6.1 - Abstraction of “riddim” – basslines
moving from musical to environmental
• 6.2 - Low frequency sound activating spaces
- articulating building materials through
vibration
• The dialogue between hearing and sensation
- felt and audible aspects affecting awareness
and perception of each other
I reflected on approaches taken to the
abstraction of riddim, from rhythmic/musical,
to smudged riddim, to drones, to building
sensation from basic components, to stutters
and plosive sensation, and modulation.
I focused on slow passages of deep undulation
as an effective point within this spectrum. This
approach found the right balance in my aim
to reference the qualities of musical riddim,
without explicit reference to musical contexts. I
intend to continue to use this approach within
sensation composition.
I also reflected on the timbral range from
materials that I had covered in the program,
including large and small objects, and subtle to
harsh sounds.
I found a comfortable point in my approach
to exciting objects, whereby I could express
the ‘potential’ for vibration energy in
materials, through moderate and appropriately
constrained resonance/vibration, without
leading into full discordant vibration sound.
By Phase 6, the overall research program had
answered my questions about the capacity of
vibrating materials as a basis for composition. I
found a flexible enough range of sounds to base
a composition entirely on vibration sounds as a
source material.
However, having reached this point, I
recognised that I did not need to limit myself
to this approach for all future work after the
conclusion of the Masters.
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SURFACE RESONANCE
Phase 6 - Summary
I also settled on the approach to sound/
sensation dialogue. During earlier research,
I had experimented with entirely synched as
opposed to ‘contrapuntal’ approaches. In the
undulation composition, I maintained a general
correlation between audible and vibration
elements, with more subtle departures, or
‘easing apart,’ enabling a communicative link
between the two senses.
The findings during this phase should be
read in conjunction with the installation and
presentation context section, which responds
more specifically to thoughts associated with
audience access and interaction with the work,
in an installed context.
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SURFACE RESONANCE
Phase 6
Table overview
Findings against principal research aims
Time/Work
Active processing
of detuned bass
while in feedback
Findings, focus,
key directions
Developing
further ‘played’
techniques
for blurring
modulation and
drones
Abstraction of
‘riddim’
Low frequency
sound activating
spaces
Tactile system as
an instrument
The dialogue
between hearing
and sensation
Real-time
application of eq,
pitch shifting,
delays in the
approach to bass
guitar feedback
generation
Microphone
feedback on the
table to best play
at the fringe of
feedback
Experiments with
earth hum
Collaboration:
progressing
ideas, move
to undulation
- tonal shifts,
but organically
smoothed and
blurred
Strongest point
in alluding to
riddim without
trappings of
explicit musical
reference
Expanding
blurring
approach to
semi-rhythmical
material, finding
undulation and
best expression
Engaging bass
feedback around
synthesised tones
More subtle
sequenced step
in tone pattern
gave a nice sense
of tonal shift
without having a
direct rhythmical
reference
Feedback on this
offered a sense
of undulation,
providing a
building block
for composition
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SURFACE RESONANCE
Findings against principal research aims
Time/Work
Composition aims
for containment
of vibration
sound
Findings, focus,
key directions
Finding a
suitable frame
for expressing
vibration sounds
– referencing
initial
inspirations
about all material
having ‘potential’
for vibration
energy to be
expressed
Abstraction of
‘riddim’
Low frequency
sound activating
spaces
Tactile system as
an instrument
The dialogue
between hearing
and sensation
Found that I am
comfortable not
working with
full range, harsh
sounds
Aim for sense
of containment
in the vibration,
using hand
dampening
Expand range of
materials – use
steel drum, new
miking approach
Pushing at fringes
of sound / tactile
interaction
For vibro-acoustic
structure,
following from
closely correlated,
to against
each other, to
independent
vibration,
settling on closely
matched with
more subtle
departures
Structure aims
to maintain
a general
correlation
between hearing
and sound, but
with some more
subtle moments
of departure,
where elements
support each
other but don’t
strongly contrast
Group feedback,
thinking about
installation
context
Again suggesting
ways to
best frame
composition
and how it
is presented
- considering
installation
context ‘attention
span’
Consider how
more subtle
elements
communicate in
installation, and
how to best frame
the experience
End point: finding a comfortable and effective frame for composition, which addresses my research questions. Provides
basis for ongoing work with vibration, and future investigation of installation approaches.
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SURFACE RESONANCE
Phase 6.1 - Riddim
Phase 6
6.1 - Riddim
During Phase 6 I focused on slow passages of deep undulation, which found the right balance in my aim to
reference the qualities of musical riddim, without explicit reference to musical contexts.
This period involved significant
experimentation with generating vibration
sensation source material, with a particular
focus on processing bass guitar feedback to
trigger an ebb-and-flow effect in the sensation.
As before, I tried to keep the link to riddim that
had motivated earlier work. I had sufficiently
mapped the territory to suggest what worked
most successfully. I:
• started from recordings of musical bass
• filtered basslines and recorded their effect on
a space
• ‘smudged’ and processed basslines to get a
sort of rhythmic effect on the body, when
fed into the table, but it was too overtly
musical
• worked on raw sine and saw waves and used
flanging and phasing to step and shift the
tones, but decided that it wasn’t organic nor
subtle enough
• had success with drones. However, these
didn’t capture the essence of riddim, such
as shifting patterns with frequency changes.
These elements were necessary to draw on
the sense of vibration gripping the body
in different ways with different tones, in a
riddim-like way
• applied short passages of stuttering, more
plosive vibrations, which were engaging but
on a different tangent from the riddim basis.
They did not offer sensory deactivation, or
relaxation (components that I considered
essential in the experience of musical
riddim)
• plucked, detuned and rested the bass
guitar on the table to generate modulated
feedbacks. However, this modulation
was strong and ‘punctuated,’ with a short
envelope, leading to a vigorous sensation
effect that was not seductive
• knew interactions of recordings or tones
could yield interesting phase interference
effects, which, when subtly applied, helped
to give body and texture to the sensation
• had success with pitch shifting material
downwards to hit the sensation ‘sweetspots’
Considering these aspects of the research, I
recognised that I had followed a trajectory
from rhythm, to drone, to modulation. I had
touched upon and was motivated to further
explore undulation of bass material.
For this research, undulation could be
understood as material offering subtle and slow
movement in tones and pattern, but without
the explicit musical reference to rhythm.
Alternatively, where the sounds/sensations
would gently move into and almost out from
deep, strong tones.
I developed a number of tests to further my
application of bass undulation, particularly for
sensation.
The results of these were employed in the
undulation composition.
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SURFACE RESONANCE
Phase 6.1 - Riddim
Revisiting detuned bass resting on
the table, to work around the edge of
feedback
With the bass guitar signal sent to the table,
I rested it on the table with highly detuned
strings.
I experimented with real-time pitch shifting
and signal processing of the guitar signal.
Processing included signal compression, low
pass filters and tape delays.
This approach built on what I had applied on
pre-recorded segments. However, processing
the sound as it was made offered more dynamic
and intuitive control of the vibration effect.
The combination of effects offered a generally
gentle undulating and textured signal without
the strong modulation I had previously
experienced.
Building on this, I used a microphone to pick
up the sounds from the table or guitar itself.
Like the guitar, this signal was fed into the table
using similar signal processing, particularly
strong downwards pitch shifting.
This was very successful. Placing the
microphone at different distances helped
me to play with the threshold of the point of
feedback, and manipulate the way the vibration
fell into and out of this.
Strong energy by using earthing
feedback
conductive surfaces and my own hands. This
included ‘floating’ my hand around the plug,
but not contacting, whereby some activation of
the earthing field was obtained, but I was able
to explore the boundaries of a strong tone.
What might have been a simplistic signal as
audio was quite engaging as a sensation.
Collaboration
I collaborated with Jason Heller. His analogue
synthesizer offered very low frequency tones,
which were processed through delays and
feedbacks.
The signal was sent in the table, while
concurrently I employed the bass guitar and
microphone feedback as above. The bass
feedback built and escalated from the material
coming in from synthesizer.
From the riddim exploration perspective,
the material was interesting as the gritty
synthesised tones had a slight sequenced step,
offering riddim-like shifts in the frequency
generated.
The microphone feedback and collaboration
yielded a range of passages that I composed
with.
I detuned and processed the signal of a shorted
guitar lead. Depending on how I shorted the
lead (contact with positive and negative parts
of the jack plug) I could get an interestingly
coloured, very strong low frequency energy
(50Hz hum, then processed and detuned).
I experimented with pressing the lead against
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SURFACE RESONANCE
Phase 6.1 - Riddim
Addressing my research aim
At this time I had tested the different
approaches that could be taken to abstraction
of riddim, addressing my research aim about
‘how effectively I can reference riddim in
creation of sound works, and testing the
issues associated with this linkage to musical
contexts.’
Importantly, my reference point for abstraction
of riddim was not that of the dance floor, but,
as described in my proposal, the post-nightclub
experience of being outside performance
spaces such as warehouses, where riddim was
naturally abstracted as the low frequencies
passed through building structures.
At the end of Phase 6, I had developed an
approach that captured the attributes of this
movement from musical to environmental
sound, without being bound to the explicit
links to the music experience that came from
directly using bassline material.
The approach I developed recognised the
fundamental differences in perception of such
sound in a stand-alone art installation context,
from that of being in the street following
exposure to high-intensity basslines.
In the post-nightclub state, the sonic artifacts
of building vibration can become the
perceptual point of interest.1
However, my early research showed that this
perception of the ‘environmental’ over the
‘musical’ elements did not directly translate
when the sound was presented as a stand-alone
experience.
When listening back to recordings from
outside nightclubs, or blurred riddim activating
spaces, the underlying rhythmic properties of
the bass would seize my attention, over that of
the environmental artifacts I was interested in.
Through this testing and later experiments,
I concluded that the fundamental musicality
of the underlying rhythmic pattern created
such strength of association to music, that
when using music-based material in this
way I wouldn’t be able to effectively separate
the audience experience from this musical
reference point.
Recognising that this challenge was inherent
to the different presentation context and
listener experience, I moved to more abstracted
approaches.
The use of undulation, while longer in its
envelope than riddim, still captured the sense
of materials responding differently to particular
frequencies of sound, and the activation and
release that came from musical basslines as
they passed through a space. By avoiding
direct use of bassline riddim, I could free up
the experience to be about this environmental
response.
From a pure sensation perspective, I also
recognised that undulation represented an
experience that was remote from that of
riddim, being more suggestive of a mechanical
context, such as vibration from engines.
The reasons for taking such an abstracted
approach to vibration were much the same
as for my approach to sound. However, the
particular properties of vibration perception
were also a significant factor that helped
steer my approach to the smoothing out and
stretching the change in frequencies.
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SURFACE RESONANCE
Phase 6.1 - Riddim
I found that, when engaging critically with the
table, the listener would become acutely aware
of shifts in tone such as from a bassline.
The mode of experience, where a person was
directly engaged with the vibrating surface,
meant that a true bassline pattern would be
too coarse and dramatic (compared with low
frequency sound, which is naturally ‘smoothed
out’ within a space).
Therefore, the use of undulation offered a
way of touching on the sense of activation
and release that came with bassline
riddim, although in a different mode of
communication, more tailored to vibration as
a medium.
1. This is perhaps because of their contrast to the preceding
intense musical experience, where there has already been
a strong exposure to musical bass. The spatial aspects may
also be a significant factor, as there can be a very different
proximity to the nearby vibrating material, compared with
the remote sound system that stimulates it.
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SURFACE RESONANCE
Phase 6.2 - Materials
Phase 6
6.2 - Materials
During Phase 6, I worked with new materials and refined my techniques for sound generation. This helped
me to develop a range of sonic textures that worked well together, without the need for supporting processed or
synthesised sound.
Reaching this point helped to satisfy my research interests around how vibrating materials might be used in
composition.
Building on my sensation experiments, I
prepared a range of engaging sensations
through the table, without complementary
sounds.
To progress a whole audio-tactile composition,
I activated a selection of materials through the
table, using the material selected for bodily
sensation.
Again I recorded a number of passages with
windows and metal, but unlike with the ‘March
table project’ I didn’t employ smaller material
such as glasses, bolts etc. I also worked with a
large oil drum, activated directly by a vibration
actuator, rather than via the table.
When activating the material, I dampened
the surfaces with my hands to allow control
over how much the sound developed into
chaotic rattles. This offered a containment to
the sound, in that the potential for vibration
was expressed, but not fully realised as a noisy
effect.
I used a pressure zone microphone in this case,
as it had a 180 degree pick-up pattern, which
better captured the overall character of the
vibrating surfaces.
I also tested some recordings with contact
transducers. However, my focus was more
on the freely held microphones because of
the flexibility for changing placement as the
sounds altered in character and intensity. The
microphone also offered a deeper and more
complex sound.
Addressing my research aim
This work helped to satisfy my research
aim concerning the articulation of building
materials.
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SURFACE RESONANCE
Phase 6.2 - Materials
Through earlier compositions and
tests, I had established that I could
reveal a wide range of sounds
from vibrating materials, from
peripheral, sensation-augmenting
sounds, to extreme rattles and
distortions.
Understanding this potential
range helped me recognise that
moderate, contained vibrations
were most complementary to my
research aims and the vibration
aesthetic I had developed.
By adopting this approach I could
layer a more complex range of
sounds than with gutterglass, and,
in contrast to the ‘March table
project’ experiments, the sounds
also worked together naturally.
I had investigated artists who employed
resonance of large strings1 or surfaces,2 those
who worked with smaller, directly excited
materials,3 and those who generated deep
bass and corresponding resonance and/or
vibration.4
Acknowledging already covered areas, and
appreciating the unique ability of the vibration
table, had led me to a more internalised/
personal approach to sound generation, where
I was physically engaged through touch in
the vibration and sensation when making
recordings.
Having found an enjoyable and
intuitive approach to working with
vibrating building materials, I also
had shown that the audible aspects
of compositions could be based
principally on this source.
I had generated a range of sounds that
didn’t require augmentation or heavy effects
processing to render an interesting and
engaging result.
As these less dramatic sounds had a smoother,
less punctuated character, they were also more
suited to combining with vibration. The more
gentle envelope was particularly appropriate
when subtly separating the timing of the
vibration and sound. The departures in timing
could also be used more carefully as an effect,
rather than a disconcerting by-product.
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SURFACE RESONANCE
Phase 6.2 - Materials
This overall research trajectory satisfied my
research aims in this area, and developed a
solid foundation for future application of my
ideas.
1. For example, Alan Lamb
2. For example, Jon Mueller
3. For example, Jeff Jerman, Untitled Sound Objects
4. For example, Randy Yau and Scott Arford, Zbigniew
Karkowski, Francisco Lopez
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SURFACE RESONANCE
Presentation
Installation thoughts and the examination presentation context
Page 88
SURFACE RESONANCE
Presentation
Presentation
Installation context feedback
This section is about the questions, tests and discussions with others on the installation and presentation of
works.
The compositions and their presentation lead to engaging an audience in vibration and vibro-acoustic
experiences, developed to answer my research questions and express my ideas and inspirations. However, the
purpose of the research was not to cover the field in terms of installation for vibration, or to explore the full
range of ways in which materials can be activated into vibration, such as activating the space, or installing
vibrating materials.
This section provides the background to the way I approached installation and audience feedback in my
research.
Intended installation approach
The intended installation approach is to use
the table, or iterations of this (such as a larger
vibrating area, suitable for lying or sitting) with
a close stereo or quadraphonic loudspeaker
arrangement.
I would aim to offer an enclosed experience, by
presenting the table within a small, darkened
room or partition, and using the location of
loudspeakers (as an indication of the listening
location) and passage into the space as a
passive invitation to the listener to touch, sit on
or lie on the table.
The ideas leading to this approach have been
developed over the course of the program,
through dialogue with others experiencing the
table and the works.
Ideally, with funding, I would offer a more
constructed approach to the vibration
installation, so that the table or a variation
from this was integrated into the installation
space. However, I intend to keep to an
experience that invites sitting or lying, rather
than just standing, as this offers a greater
bodily experience and sense of being within the
sound and vibration.
My thinking on spatialisation of sound is in
keeping with this. My initial compositions
included quadraphonic (plus vibration) mixes.
I found that, beyond very minimal/subtle
approaches, the surround effect was too
perceptually engaging for the listening sense,
which worked against the aesthetic I wanted
from the combination of vibration and sound,
where the auditory sense was ‘deactivated’ and
folded into the vibration experience.
Guidance from audience and other
feedback
In October 2007 (Phase 2), I installed the table
at a dub/reggae gig. I used this opportunity to
check some of the logistical issues with moving
the table, and to test how people related to it in
a public setting. The table was installed next to
a wall and setup to synchronise with the music,
supplementing the bass experience.
This installation showed highlighted the ways
that people could engage with the table, and
seeded ideas about the ‘method’ of inviting
people to it in a public context, as it related to
eventual gallery or public space installation.
I tried to both directly and casually gauge
the reactions people had to the sense of an
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SURFACE RESONANCE
Presentation
additional bodily element to music and how
this integrated into the music experience.
Interestingly, composers and musicians at the
event were more instinctively inquisitive and
came back to it, asking questions and engaging
with it by sitting and lying.
compositions, and to discuss the engagement
with the table, the nature and intensity of the
vibration experience, the way people responded
to my approaches to aligning and pulling apart
the vibration and sound components, and
installation suggestions.
I came to the conclusion that for the table
to work in installation, I needed to create
some form of ‘passive invitation,’ i.e. not to
direct people to the experience, but to allow
a curiosity, by somehow suggesting that the
table is sat on or engaged with somehow to
experience sound.
Some key feedback that helped guide my
thinking are provided under ‘audience
feedback’ below. People’s suggestions on
installation in a space are incorporated in my
comments above.
Loudspeaker positioning would be the most
simple answer to this, because an audience will
recognise an ideal listening location by virtue
of loudspeaker placement, which would lead
to engaging with the table. The gig install was
valuable in this sense, as it not only reminded
me of the potential awkwardness of the system,
but that there should be workable approaches
around this.
I discussed my ideas during the various
sessions with the Sound and Media Art
postgraduate students and with Berlin based
sound curator Elke Moltrecht, when she
attended RMIT in 2008. These discussions
really helped in refining my thinking and
confirming that I was on the right track.
Also, in late 2008, I installed the table at
RMIT and ran a number of sessions with
questionnaires. Participants included
postgraduate and undergraduate visual
and sound arts students and other personal
contacts.
I used this opportunity to present the ideas
and the experiences I aimed for in the
For the creation of new works, the main ideas
that I gained were that:
• There were a range of expectations and
preferences for the intensity of the vibration
experience but overall the experiences I
aimed for in making the works were well
received.
• People focused more critically or
intellectually on the work and phrases where
there wasn’t sound with the sensation.
The directly meshed pairing of sound and
sensation helped in ‘sensory deactivation,’
which was an effect I wanted to continue
working with.
• While there is scope to play with divergence
in the levels and intensities of the sound and
sensation elements, timing differences in
more plosive and rhythmic elements tended
to jar perceptually. I think these probably
worked against established expectations
based on the real-world experience of sound
paired with sensation, i.e. during more
dramatic or obvious sound and vibration
events, the elements tend to more tightly
coincide, because one low frequency
stimulus generates both the sound and
vibration.
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SURFACE RESONANCE
• More subtle passages of vibration might not
work for a casual listener, depending on the
way expectations were set up through the
installation. For example, if a listener lay on
the table during a subtle vibration passage,
they may find the vibration ‘insubstantial’
and not stay to be drawn into the work.
But if the installation was framed in such
a way that the listener became involved at
the beginning of the work, they may find
the more subtle passages interesting, or
appreciate them as part of the structure of
the piece.
This feedback also clarified differences
between what were effective experiments on
the interplay between the senses, compared to
engaging installation works, which may need
to be less ambitious or conceptual.
However, comments suggested that careful
framing of the experience through installation
can help engage people in more challenging
compositional structures, such as contrapuntal
passages, plosive elements or more subtle
vibration.
Audience feedback
My intended compositional outcomes seemed
to communicate well to the audience - for
example, the physical tension and release,
auditory sensory deactivation due to the
vibration, being physically relaxed but not in
a wholly disengaged sense, direct engagement
with the table in the vibration-only work, and
greater relaxation and shut down of ‘critical
analysis’ over the course of the work.
Similarly, the intended points of soundsensation dialogue were generally positively
Presentation
responded to, such as the vibration supporting
the sound, or shifting the dominant sense
throughout the work. However, a couple of
listeners felt that intended points of divergence
between totally synchronous sound and
vibration were not nearly as effective as
synchronised parts (although they understood
the intent of this after experiencing the works
and reading the supplied notes).
Generally, totally synchronous sound and
vibration seemed to be responded to most
favourably. Some listeners picked up on the
time-delay between the sensation and sound.
I knew from my early research that this is
something to which people have an acute
sense, and that I could address this by closer
loudspeaker arrangement or electronic delays.
People had a range of expectations for the
intensity of the vibration. Most found the level
of vibration appropriate to the experience and
compositions, but some wanted a more intense
experience. While the table is able to generate
a strong physical experience, I chose to use
shorter passages of this for effect within a work,
rather than providing this kind of intensity all
the time. This enables me to offer a broader
range of communication, and greater subtlety
in the sound-sensation dialogue.
I also recognise that while the table can offer
an intense experience, this is not comparable
to intense sensation from very loud low
frequency sound. Sound can cause greater
activation of the body through the vibration
of the air and of the organs, whereas the deep
textural oscillations through the table engage
in a different way that is more about the body’s
interaction with a vibrating surface. I haven’t
tried to match or repeat the sound experience
that people used to bass heavy music
performance might be seeking.
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Comments from three people suggested that
when hearing just sound (before having access
to the table), there was a psycho acoustic
suggestion about what the vibration element
might be. I inferred that this would likely be
what we might expect from real-world soundsensation experiences. The works aimed to play
with this expectation.
However, having people hear the sound first
was not helpful for the paired experience, as it
established expectations about the vibration.
This suggested that in installation it would be
important to ‘contain’ the experience so sound
and vibration are experienced together (i.e.
avoid an audience wandering around listening
without sensation).
Although there was generally very positive
response to the combination of sounds and
vibrations, there were also outlying responses
on the mixture of the mediums, with one
listener suggesting that they would have
preferred just having the table, but another
preferring just the sound from loudspeakers.
Presentation
supported. One listener suggested something
like a reclined chair, although others noted the
connotations to a massage chair.
One participant suggested baffling the table
to minimise the audible noise during the
vibration-only work. Another suggested
exploring spatial vibration with multiple
devices in future.
In the undulation composition there was a
passage where the vibration was very minimal,
intended to sit underneath the sound before
rising to prominence. Some feedback suggested
that in a normal ‘walkthrough’ installation
sense, there was a risk of the listener leaving
too soon. We discussed how this might be
addressed through changing the works, or by
defining the listening experience, such as a
process of walking into the space at a set time,
or enabling people to ‘push play’ to experience
the whole compositional arc.
The works stimulated a range of ‘recollections’
in the listeners, such as: ‘lying in the ocean’,
‘transport, in particular flying’, ‘pins and
needles’, ‘being in an earthquake’, ‘feeling like
something is going to fall down’, ‘trance-like
meditative state’, ‘synaesthetic,’ ‘addictive’. After
the works finished, people described feelings
such as ‘fuzzy’ or ‘disoriented’ (these were
positive descriptors).
People were comfortable (or enthusiastic)
with lying to engage with the work, but
recommended a softer surface, a longer, more
‘bed-like’ setup, and exploring materials
that moulded to the body. Using pillows
to minimise head vibrations was strongly
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Presentation
Drawing
BaSS(ic) EFP (Enhanced Floor Project)
Eliot Palmer
Logistical and technical notes
Scale:
Date:
Drawn:
Axonometric
01.08.06
JF
Around May 2007 (Phase 2) I completed
construction of my vibration table
instrument, working with an engineer,
designer, acoustician and steel welder to
construct a steel frame with MDF top.
This was an 8-12 month process of technical
and design refinement, aimed at creating an
instrument, which principally activated the
body without causing unneeded sound.
The facing images indicate some of the
design work that went into making the
table - table design (assistance from Jerome
Frumar) and calculating materials usage and
mass.
My early (theoretical and testing) research in
SIAL, and presentations during the course of
the research also assisted my understanding
of the electronics setup component of using
the table in an installation context.
For example, in an installation for a dub/
reggae gig in October 2007, I had to consider
compression, limiting, equalisation and
delays, to best align the vibration to the music
being played through the soundsystem.
Model for oor system
Total Floor
H
Frame length
65x35x3.0 RHS
H
Frame width
65x35x3.0 RHS
H
Cross length
65x35x3.0 RHS
H
Cross width
65x35x3.0 RHS
H
Frame Legs
35x35x3.0 SHS
H
Central Box
H
18
1500
65
35
65
35
1430
35
1
total weight
true length kg mm
1430
0.00425
6.0775
1
total weight
true length kg mm
1430
0.00425
6.0775
4
total weight
true length kg mm
1028
0.00425
4.369
beams
L
W
257
35
35
31.95
total weight
true length kg mm
2860
0.00425
12.155
beams
L
W
65
14.2
2
beams
1430
total weight
kg m2
total weight
true length kg mm
2
2860
0.00425
12.155
beams
35
L
W
L
W
30
30
kg
L
W
25
1430
1430
65
Sur m2
2.25
beams
L
W
H
1500
L
W
137
Allowance between actuator and
bottom of feet
L
W
30
Buttkicker
1500
1500
275
Top plate
woodlogic Customwood 18
TL
TW
TH
140
140
5
Total pipe length m
9.608
Sum weight kg
77.784
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Appendices
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Appendix A
Appendix A
Background research notes
Research testing notes taken from earlier
Graduate Certificate study at SIAL, 2004.
Provided for additional background on sound/
sensation research.
The following gives an overview of the low
frequency sensation tests conducted as part
of my design research project. The tests were
undertaken to aid an informed design process
for my music vibration system, as well to gain
further understanding of the role of sensation
in amplified music experience.
Each test evaluated a different aspect of low
frequency sound, vibration and relationships
of these aspects to music experience. Tests
took an average duration of forty minutes, with
sound used intermittently throughout the test
duration. The tests, which took place over two
nights, were conducted with one participant
and myself in the room. Three tests were
performed with five participants, three females
and two males. Mean age of participants was
30 years.
Tests were conducted in a storage space next to
the SIAL N space. The room dimensions were
measured and room resonance calculations
were applied to determine a listening location
that was least influenced by room acoustics.
Once installed, the audio system was tuned
to yield a reasonably uniform response at low
frequencies.
Before testing, sound level readings were taken
and used to calculate safe listening periods for
participants in accordance with Workcover
Safety and Ethics Guidelines. Maximum
sound levels were set in accordance with these
guidelines. However, participants could choose
to have the sound levels reduced at any time if
they wished.
Test 1: Swept, pulsed pure sinusoidal tones
from 15Hz – 100Hz. Acoustic system engaged
for the entire frequency range. These tests were
to evaluate relationships between frequency
and sensation in the body. They were also used
to familiarise participants with high-energy
low frequency sound and to stimulate an
articulation of bodily sensation.
Test 2: Swept, continuous pure sinusoidal
tones from 15Hz – 100Hz. Acoustic system
filtered with substantially less energy below
70Hz, vibration system engaged below this
point. These tests were to identify the types
of sensation differences between acoustic and
vibration energy and the transitional points
between the two systems as identified by
participants.
Test 3: Music test tracks played through the
acoustic/vibration system. The system was
alternated between two configurations: Full
frequency range acoustic (as in test 1) and
acoustic/vibration (as in test 2). These tests
were to evaluate the effectiveness of vibration
technology over a range of test tracks with
different frequency emphasis.
Findings:
Test 1: Swept, pulsed pure sine tones,
acoustic only.
Results were hugely variable. While some
participants shared similar bodily sensations/
responses to certain frequency ranges the
overall range of responses and sensitivities
suggests no uniform conclusions. I believe that
aspects that contribute to this variation are:
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- Very different sensitivities of participants.
While some participants would clearly
articulate frequency specific sensations, others
did not identify any specific responses. Overall,
female participants provided much more
articulate responses to sensation and other
effects.
- Audio system interference. Due to safety
guidelines, system performance did not allow
enough acoustic energy to explore acoustic
sensation adequately. Also, the audio system
performance was not entirely flat in response.
This was because of loudspeaker design
artefacts as well as relatively crude methods of
calibration.
- Room interference. The reverberant
properties of the room in terms of both low
frequency resonances and distracting resonant
noise (from air conditioning, outside stairwell,
windows etc) affected sound energy and did
not provide a critical listening environment for
participants.
- Test procedures. My approach to prompting
feedback from participants changed thought
the tests and this may have affected the level of
feedback.
Findings of interest:
Sensation
My expectation from observation of other
research was that bodily sensation would shift
from area to area with an increase of frequency,
largely in relation to resonant cavities (in
or around organs) in the body. However,
sensation shifted from organs (eg in belly or
chest) to areas (eg legs, upper body) to surface
skin effects and zones such as the ears or nose,
Appendix A
and would shift back and forward throughout
tests. Other effects included a sense of vertigo
and a feeling of tiredness occurring with
specific frequencies. This suggests the myriad
of low frequency effects found in amplified
music as well as the multiple senses engaged.
I believe that significantly more absolute
results would only be achieved with very high
sound pressure levels in a highly controlled
environment.
Space
One participant identified certain frequencies
as occupying different heights and locations
in the room, shifting with changes in
frequency. I am uncertain as to the acoustic
effects (from loudspeakers and the room)
and the psychoacoustic contributions which
generate this response. Experimentation with
‘placement’ of low frequency sound and its
more tangible, locatable properties could be
investigated through more tests combined with
room resonance analysis. This would inform
composition that explores interpretation
of specific spatial experience through low
frequency sound.
Skin
There was a correlation between three
participants in identifying a frequency
where the effect of sound became less
‘bodily’ and more of a skin surface effect.
Two participants identified this as a tingling
sensation rather than an internal sensation,
and one described a feeling of being cold. As
no other sensation effects were as consistent
between participants this frequency may
identify a predictable transition point between
sensation and auditory perception of sound.
The frequency sits near my estimated ‘cut-
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off ’ frequency determined to be the upper
limit of effectiveness for a vibration system.
Investigation of this relationship will be
extremely interesting as I believe it is currently
unexplored.
Test 2: Swept, continuous pure sine
tones - vibration/acoustic system.
Outcomes from these tests have suggested
that identification of forms of fusion
between vibration and acoustic perception
is quantifiable, but that the articulation of
transitions between these senses is difficult.
Findings of interest:
Sensation
By comparing acoustic energy with direct
vibration energy I have come to understand the
fundamental differences between these modes
of communication. Using the vibration floor
did not simply replace the acoustic energy with
a more direct sensation interface. The qualities
of sensation were fundamentally different,
being more grounded in the body. Overall, at
most frequencies participants found that they
were more comfortable with vibration energy
than with the acoustic only system. Vibration
sensation ‘bodily placement’ did not correlate
with findings from the acoustic only system,
suggesting that the way the body is excited by
direct vibration is significantly different. While
some effects were specific to the vibration
system, such as a sense of the feet shaking, the
range of sensations experienced were board,
including effects in the upper body, face,
legs and back. This indicates that a vibration
system is appropriate for generating a range
of frequencies and spectral content and that
its effects are not limited to feet or leg focused
Appendix A
sensation.
Perception
Perception of auditory effects was also affected
by the vibration system. Most participants did
not perceive acoustic energy in the room until
acoustic levels were much higher than normal
perceptual thresholds. I believe that this is
because vibration and acoustic energies mask
each other, with increased vibration effects
reducing acoustic perceptual sensitivity.
One participant identified a frequency where
they felt that their focus was flipping between
the vibration and acoustic system, at a point
where both energies were perceived to be at
similar levels. This suggests that, although there
is some degree of perceptual blending with
combined vibration/acoustic energy, potential
exists for sensory confusion when the two
sources of information are similar. Similarly,
tests with music tests tracks suggest that
vibration and acoustic perception, although
working together, compete with and affect each
other’s characteristics.
Transition
Four of the five participants identified a
specific frequency where perception of energy
shifted from the vibration to the acoustic
system. This frequency was the same for all
four participants (within a 1Hz tolerance).
This finding illustrates that specific transition
points between perceptual modes can be
identified. However, I believe that this point
is fundamentally determined by loudspeaker,
vibration system and room characteristics.
With further analysis I intend to develop
situation-specific system tunings to explore
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this aspect of low frequency experience in
relation to the electro-acoustic environment.
This research will assist system calibration
as well the development of sound and music
composition approaches that enhance
perceptual fusion in vibration system
installations.
Envelope
Further tests were briefly conducted with four
participants, exploring sensation differences
when using continuous test tones compared
with the pulsed tones used in initial tests. These
tests did not provide definitive conclusions.
However, the perceived relative strength of
vibration effects did change when the envelope
of test tones was filtered. These strength
characteristics were not consistent across
the full frequency spectra, but the previously
observed transition frequency from vibration
to acoustic systems remained the same.
Preliminary findings suggest the significance
of rhythm envelope for both acoustic and
vibration perception. This indicates that in
future composition for vibration systems,
envelope as well as spectral content and
psychoacoustic effects will have to be
considered.
Test 3: Music test tracks played through
the acoustic/vibration system.
The complex responses to music reproduced
through the acoustic/vibration system have
developed my understanding of personal
engagement with music technology and related
composition characteristics that affect electroacoustic music experience. Overall, responses
were mostly consistent between participants
and preferences towards vibration system
Appendix A
reproduction were expressed.
Findings of interest:
Engagement and Association
Most participants quickly found that they
became more involved with music when the
vibration floor was engaged. In addition to
compelling more attention to the music, the
floor itself became something to interact
with and was missed when deactivated.
This association was strongly noted by most
participants while listening to the first piece of
music, with later tracks evoking more critical
descriptions of comparative effectiveness.
Descriptions included: the floor creating a
nicer experience because sensation was more
bodily; feeling more involved and consumed;
increased awareness of high frequency
sound; increased awareness of low frequency
sound; quick association with the vibration
experience; and that the floor created another
level of interaction, or relationship. In the
context of comparative testing against the
acoustic only system, the vibration interface
itself often became essential to the music
experience, translating and extending the
qualities of the music used.
Acoustic Noise and Masking
In most tests the acoustic only system was less
enjoyable for participants. When in acoustic
only operation the strongest responses were
that the sound failed to engage, being washed
out or lacking in weight compared with
vibration assisted reproduction. Because the
acoustic energy did not involve the body as
directly, low frequency information was less
tangible and less defined. One participant
found that it was harder to interpret the
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Appendix A
bass with the ears only and other responses
indicated that the music seemed more muffled
or muddier. The extra acoustic energy usually
detracted from the qualities of the music, as
the increased air pressure was less comfortable
and excited more noise from the room itself. In
some cases the extra sound was perceived to be
a less enjoyable force, pushing at participants
rather than engaging the body directly.
frequencies (20-45 Hz) where the contribution
of the floor was felt to be more essential. Tracks
where frequency emphasis was centred closer
to the upper operating frequency of the floor
still benefited. However, vibration effects
became more noticeable as buzzing or were
perceived to be located in the floor, rather than
a logical extension of audible sounds. This may
partly be due to the type of technology used.
I have observed that when engaging full
frequency acoustic information, the added
sub-bass reduced overall intelligibility of music,
masking the higher frequency information.
This effect may have been more pronounced
due to the small size and reverberant properties
of the room.
The added depth given through the floor in
the lower frequencies was not substitutable
with acoustic energy, which failed to deliver
the same type of internal sensation, partly due
to (relatively) low sound levels as well as its
overall characteristics. However, in the higher
bass frequencies acoustic and vibration energy
became more similar in sensation qualities.
I believe that this finding illustrates a key
aspect of amplified music experience. At many
large-scale events the acoustic energy excites
vibration in the room, creating resonance along
surfaces such as the floor - accessing the body
through a direct physical medium. The acoustic
energy itself does not contain all the properties
needed to achieve an enjoyable response.
Rather, it excites vibrational energy to further
enhance music experience. Chasing this level
of physical excitement requires acoustic levels
that are harmful to hearing and can detract
from the music’s accessibility by masking other
sounds. This finding would need to be tested in
larger scale systems to verify its accuracy.
Frequency
Each test track chosen had a different
frequency emphasis, enabling participants
to evaluate the musical effectiveness of
vibration technology over its entire operating
range. Results favoured pieces of music with
frequency content extending into the very low
Envelope
Participants favoured the vibration interface
in tracks where low frequency rhythm was not
overtly punctuated, having a rolling or fuzzy
quality. Dub and Drum ‘n Bass tracks with this
type of bassline produced best results. More
punctuated rhythm appeared to highlight
differences between acoustic and vibration
information, perhaps because the chronological
space of definite ‘beats’ promoted more
critical perceptual processing. The envelope of
synthesised bass also appears to determine the
characteristics of the interface. Tests suggest
that sine wave bass has a more embracing tonal
quality with saw waves having a comparatively
sharp or abrasive effect. I intend to explore
this aspect with a greater range of test tracks
and compositions in the future, to assess the
effectiveness of sensation properties of different
genres of music.
Fusion and Competition
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Participants found that when low frequency
was distinctly different from high frequency
information the floor failed to enhance music
experience. Rather, with acoustic and vibration
senses processing separate information, the
floor became a distraction and could be
disorientating due to lack of cohesion. This was
primarily noticed on one track, which had an
atypical gap in information between low and
high frequencies. All other tracks contained
some degree of acoustic ‘artefacts’ in upper
harmonics of the predominant (vibration
sensed) bass information, which possibly aided
in tying sensory information together. I believe
that this aspect strongly relates to the envelope
characteristics noted above, as sensory gaps
appear to be more acutely noticeable when
music is punctuated.
Timing
One aspect that determined the effectiveness
of the vibration interface was the arrival timing
of sensory information. Because sound travels
through air slower than electrical signals,
information sent to the floor had to be delayed
in respect to its distance from the loudspeakers.
Delay between arrival times could reduce
the perceived clarity of the music. This was
most clearly noticed with music having highly
punctuated rhythm and at the beginning of,
rather than during, passages of low frequency
information. In this sense vibration perception
is similar to auditory perception, as sound
also suffers from reduced intelligibility when
acoustic events are delayed from each other.
A large-scale vibration installation would
require a range of delay times over its surface
to compensate for increased distance from
Appendix A
loudspeakers. To understand required delay
intervals and allowable timing offsets I intend
to assess this aspect of perceptual fusion. I
believe that delay offsets would be allowable
within fairly broad guidelines, with reduced
intelligibility having a relatively wide margin of
error compared with sound. However, this may
shift in respect to frequency and amplitude as
well as individual sensitivities.
Scales of Perception
When combining vibration and auditory
information, one of the most fascinating
findings is the sensitivity difference between
the two forms of perception. Sound is
perceived in a logarithmic scale, using the dB
unit of measurement. However, vibration is
closer to a linear scale of perception. Therefore,
small changes in dB level result in large
changes in vibration level.
This was evidenced when small adjustments
were made to levels being sent to the
vibration floor. Incremental adjustments
that are barely noticeable to hearing (1-2dB)
produced significantly more apparent levels
of vibration. Also, as levels increased within
a track, vibration effects became extremely
pronounced, to the point of being overbearing.
Although intensifying the experience it
significantly altered the balance of the music in
an undesirable sense.
This effect was reduced through system
compression, which adjusted levels sent to the
floor to fall within a more restricted dynamic
range. However, as audio adjustment and
tuning uses a dB scale of measurement, these
settings were fairly arbitrary.
In order to understand how to best tune and
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SURFACE RESONANCE
manipulate a vibration system that uses an
acoustic point of reference I will need to more
fully understand the relationship between
both senses. In amplified music, as well as
everyday life, acoustic experience incorporates
vibrational energy. In creating a vibration/
acoustic experience I will need to further
understand the way that we perceive this
combined force.
I have not yet seen any exploration into the
combination of these forms of perception.
A significant amount of studies exist on
perception of sound. There is also research into
perception of vibration, using different forms
of measurement. Significant research into the
combination of senses and related perceptual
effects has yet to be investigated. Exploring this
aspect of acoustic experience will not only aid
an informed design process but also develop
further understanding in an under-researched
field.
Technical Notes
Frequency Analysis:
Each test track was processed in audacity after
being normalised. Analysis of three to five 30
second sections of each track were exported
into excel, where they were sorted and edited
according to level. Once listed in excel, average
concentrated values were evaluated and tracks
were listed according to frequency emphasis.
Chosen tracks had emphasis ranging from
30Hz up to 85Hz.
Room Resonance Calculations:
The test room was modelled as a rectangular
space to calculate axial modes. Two models
were generated to determine the best section of
Appendix A
the room for testing. The calculator, written by
myself in excel, incorporated input for average
room temperature, width, height and depth
and calculated axial modes including harmonic
resonances and upper and lower predictable
frequency limits.
Determination of Loudspeaker System
Tests at Rent the Rig and Warehouse Sound
Systems were undertaken to assess equipment.
Tests were done with SPL meters and overall
level capability as well as frequency response
efficiency were determining factors in system
design. The combined system had the best
balance of low bass extension and efficiency for
available budget.
Crossover
The crossover point of 70Hz was chosen from
pervious tests with smaller scale systems,
according to my personal preferences. 24dB/
octave Linkwitz-Reily crossover slopes were
used for both vibration low pass and sub
high pass. This resulted in minimal acoustic/
sensation crossover. Results suggest that the
vibration crossover roll-off would suit a gentler
slope, but this would be dependent on the
actual installation. However, I am reasonably
confident that the chosen crossover frequency
reflects a real perceptual transition point.
Vibration Tuning, System Compression:
The vibration system signal had approximately
6-10 dB of compression, with peak limiting.
The primary subwoofers (2x 18”) had no
compression, with peak limiting. The Midhigh loudspeakers (4x 15” and 2x 2” Horns)
had 2-6 dB compression, with peak limiting.
The system controller has compression over its
input. The max patch and a desk were used for
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SURFACE RESONANCE
level adjustments and compression was set in
relation to this operating range. In future tests I
intend to use software level adjustments where
possible to ensure more uniform, accurate
results.
Appendix A
nsf/pages/so_noise_exposure
Recordings and tuning:
Levels were determined in relation to
Workcover guidelines: Laeq85dB, 8hr.
Calculation: To work out a level based on a
given Leq over time (T), and a time you want
to use (t)...
Recordings were made to test the system, with
sweeps and pink noise. A pink noise test was
used for tuning and parametric eq adjustments
were made according to measured octave band
levels. This resulted in a ‘flat’ bass response as
measured on the meter. However, anomalies
were still present, partly due to loudspeaker
design as well as the rough method of
calibration.
L(t) = Leq + 10log(T/t)
Results:
Average 45min duration:
L(.75) = 85 + 10log(8/.75)
In swept tone tests participant responses
were recorded and tabled in excel, listed by
frequency. This was used for response analysis.
Original notes were used for assessment of
response to music tracks.
Safe Sound Levels:
L(.75) =95dB(A)
All average values were below this point, with
peak sound levels well below the maximum
of 140dB(C). A B&K SPL meter was used to
monitor levels. Music listening levels were
measured in dB(Lin), average values at 112dB.
Swept tones were also within 110-117dB(Lin)
range. dB(Lin) measurements were the
acoustic reference during tests, with dB(A)
levels calculated according to previous analysis
during setup, as listed below.
Track Measured dB(C)
Rwanda
112-114
Scorn
110
Ethearalites
109
Rhythm + Sound 112
The Bug
116
Brian 2K
116
Measured dB(A)
95
95
95
93
95
97
Reference for Workcover:
http://www.workcover.vic.gov.au/vwa/home.
External Noise and Reduction in Level:
Whilst the system was running I walked
around the building and surrounding areas
to assess noise impact. Air conditioning
and windows were the most obvious sound
transmission paths.
System tuning offered promising results in
terms of level reduction for external areas. I
measured dB(Lin) levels in n-Space, against the
wall next to the entrance into the postgraduate
room.
I achieved a 10dB drop at sub bass frequencies,
indicating the real noise reduction potential
of vibration technology. Real benefits would
best be assessed with octave band or finer
measurements, in a variety of measuring
locations.
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SURFACE RESONANCE
Appendix B
Appendix B
Bibliography
Altinsoy, M. E. Audiotactile simultaneity of musical produced whole body vibrations. Bochum,
Germany, Institut fur Kommunikationsakustik, Ruhr-Universitat Bochum.
Altinsoy, M. E. (2003). “Effect of loudness on the haptic force-feedback perception in virtual
environments.” Journal of the Acoustical Society of America 114(4): 2330.
Altinsoy, M. E. Inter-modal effects of non-simultaneous stimulus presentation. Bochum,
Germany, Institut fur Kommunikationsakustik, Ruhr-Universitat Bochum.
Cook, P, (2002) Real Sound Synthesis for Interactive Applications, AK Peters, Ltd
Chamberlain, P. (1999). Good Vibrations: A case study of design-led collaborative new product
development in the field of vibro sound therapy. Third International Conference of the European
Academy of Design.
Delgarno, G. A vibroacoustic couch to improve perception of music by deaf people and for
general therapeutic use. ICMPC6
Griffin, M. J. (1990). Handbook of human vibration. London ; San Diego, Calif., Academic Press.
Hooper, J. (2001). “An Introduction to vibroacoustic therapy and an examination of its place in
music therapy practice.” The British Journal of Music Therapy 15(2): 69-76.
Huang, P., S. Serafin, et al. (2000). Modeling high-frequency modes of complex resonators using a
waveguide mesh. COST G-6 Conference on Digital Audio Effects, Verona, Italy.
Lamb, Alan, (Biographical Entry), [Online], Available http://www.sounddesign.unimelb.edu.au/
web/biogs/P000277b.htm, January 2007
Martens, W. L. Human-centered design of acoustic and vibratory components for multimodal
display systems. Montreal, Faculty of Music, McGill University.
Martens, W. L. (2004). Perceived synchrony in a bimodal display: optimal intermodal delay for
coordinated auditory and haptic reproduction. International conference on auditory display,
Sydney, Australia.
McAngus Todd, N. P. and F. W. Cody (2000). “Vestibular responses to loud dance music: A
physiological basis for the “rock and roll threshold”?” Journal of the Acoustical Society of America
107(1): 496-500.
Menzies, D. (2002). Perceptual Resonators for Interactive Worlds. International Conference on
Auditory Display.
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SURFACE RESONANCE
Appendix B
Puckette, M. S., T. Apel, et al. (1998). Real-time audio analysis tools for Pd and MSP. ICMC 98.
Martens, W. L. (2005). Tolerance for delay between whole-body vibration and audio reproduction
of musical sound. Twelfth International Congress on Sound and Vibration, Lisbon.
Verrillo, R. (1992). “Vibration sensation in humans.” Music Perception 9(3): 281-302.
“Wire Music,” article, Australia Adlib, http://www.abc.net.au/arts/adlib/stories/s873159.htm
August 2009
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SURFACE RESONANCE
Appendix C
Appendix C
Discography
Asano, Koji, Sunshine Filtering Through Foliage, Solstice, [CD], 1999
Asano, Koji, Momentum, Solstice, [CD], 2000
Behrens, Mark, Integraçao, Sirr [CD], 2004
Catlin, Tim / Mueller, Jon, Plates and Wires, Crouton, [CD], 2007
Cook, Perry, Real Sound Synthesis for Interactive Applications, AK Peters, Ltd [CD], 2002
Charles, Xavier, la neige attend la neige, a bruit secret [CD], 2004
Foton, Clicks and Cars, (Exhibition description and Video), [Online], Available, http://foton.be/
en/projects/clicksncars, March 2007.
Galbraith, Alastair / De Gennaro, Matt, From the Dark (South Island), Xeric [CD], 2006
Glass percussion project, intermezzo, Eugene Ughetti [CD], 2008
Hrvatski, Owls/Souls Rotten, (Appears on Various: Attention: Cats), Reckankreuzungsklankewerk
zeuge, [12”] 1998.
Hrvatski, Oiseaux 96-98, Reckankreuzungsklankewerkzeuge, [CD] 1999.
Jah Warrior, Dub from the heart, Jah Warrior Records, [LP] 1997.
Jerman, Jeff, Instability Studies, Anomalous Recordings [CD], 2003
Karkowski, Zbigniew / Davidson, Xopher, Function Generator, Sirr, [CD], 2003
Kirkegaard, Jacob, 4 Rooms, Touch, [CD] 2006.
Lamb, Alan, Primal Images: Archival Recordings 1981-1988, Dorobo Records, [CD] 1995.
Lamb, Alan, Night Passage, Dorobo Records, [CD] 1998.
Lucier, Alvin, I am sitting in a room, Lovely Records, [CD] 1990.
Lux Mammoth, Hertz Circus, Bloodstar, [CD] 2000
López, Francisco, Temizlemek [extract cited], Linea Alternativa [CD],1998
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Appendix C
Pinch, Underwater Dancehall, Tectonic [CD], 2007
Piccinini, Patrica, the breathing room (Exhibition description and Video), [Online], Available
http://www.patriciapiccinini.net, April 2007
Sunn O))), Black One, Southern Lord [CD], 2005
Scorn, Plan B, Hymen, [LP], 2002
Scorn, Stealth, Ad Noiseam [CD], 2007
Tenney, James, The solo works for percussion, Hat Art, [CD] 1998.
The Artbreaker, Pull out the whiskey noodle, More Recordings, [Web release] 2008
The Bug, Pressure, Rephlex, [LP] 2003
Tsunoda, Toshiya, O Respirar Da Paisagem, Sirr [CD], 2003
Tsunoda, Toshiya, Extract from field recording archive #2: The air vibration inside a hollow, Häpna,
[CD] 1999.
Tsunoda, Toshiya, Extract from field recording archive #3: Solid Vibration, Infringitive [CD], 2001
Untitled Sound Objects (Pi Lang and Zimoun), installation videos, http://www.untitled-soundobjects.ch
Von Hausswolff, Carl Michael, Strom, Raster-Noton [CD], 2001
Yau , Randy and Arford, Scott, Infrasound, (performance), Liquid Architecture 4, Melbourne 2003
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Appendix D
Appendix D
Original Proposal extract
DEGREE:
Master of Arts
BY:
Project
WITHIN THE SCHOOL OF:
Art & Culture
TITLE OF THESIS/PROJECT: Physical in Sound: An exploration of vibration and sensation
within experience of sound
SUMMARY OF THESIS/PROJECT:
This project will explore audible resonance and vibration in architectural spaces; and the physical
sensation of sound, felt as vibration in the body. Through composition and installation, I intend to
explore characteristics of these and the associations they carry to experiences of sound and place.
SUPERVISORS AND CONSULTANTS (Please state affiliations):
Senior Supervisor:
Darrin Verhagen (School of Art, RMIT)
Supervisor:
Dr Philip Samartzis (School of Art, RMIT)
3.
THE RESEARCH PROGRAM:
3.1
sound
Title: Physical in Sound: An exploration of vibration and sensation within experience of
3.2
WHAT? Brief Description:
This project focuses on felt and heard vibration, how they are perceived and how they contribute
to the experience of sound in a space. Through composition and installation I aim to explore
vibration as a product of low frequency (i.e. bass or low pitch) sound, extracting material from
musical contexts where sensation from sound is emphasised.
As low frequency sound passes though a space it can stimulate vibrations in the building
structure. These vibrations may be experienced physically, through the transmission of energy
from the building and into the body, and/or may create vibration sound that is experienced
aurally, such as rattles from fixtures or windows.
My interest is in the characteristics of these vibrations and how they may convey connections
between sound and the physical aspects of the body or a space. I will explore the idea that
vibration, both heard and experienced physically, can change a persons perception of sound. I aim
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Appendix D
to do this through a series of compositions/presentations, culminating in either a sound/vibration
installation project in a gallery or a live performance using vibration sound.
The research includes development of a specially designed 1.2m2 tactile “floor” system that
translates sound into strong vibration that may be heard and/or felt through touching or standing
on it. This will be used to create vibration material for composition. With this I intend to explore
relationships between the felt and audible aspects of vibration and how each affects perception
and awareness of the other. I will explore possibilities of using the tactile system in performance as
an instrument and in installation as a way to create physical sensation for a listener.
The objective of this project is to develop compositions/installation that communicates my
findings on felt and heard vibration. I aim to create works that draw association to listeners’ past
experiences and engage with the way vibration is perceived. I also aim to incorporate vibration
technology into sound installation works. To achieve these objectives I ask the following research
question:
Through sound design and composition incorporating sensation technology, how can
I use physical vibration to draw attention to the role of the body in the experience of sound, and
how can I draw upon vibration in musical contexts to achieve this?
Influences in work looking at vibration include the “Infrasound” performances by Randy Yau/
Scott Arford and Koji Asano’s “Rift in the cloud”. These use low frequency sound to stimulate
resonance and vibration, drawing attention to architectural and acoustic qualities of a space.
These works articulate ideas of interest around characteristics of vibration (such as rhythmical,
tonal or spatial qualities) and their relationship to low frequency sound. I also intend to focus on
harmonics in vibration, and the tonal connection between low frequency sound and related high
frequency vibration. In investigating this principle I am inspired by the work of Alan Lamb, whose
compositions with large scale wires engages the qualities of harmonic vibration in objects.
In exploring these themes and characteristics within my own work, I am focusing on
environments with a strong and unique association to felt and heard vibration. These are specific
contemporary “dance” music performance contexts, where high levels of low frequency sound (as
bass in music) stimulates physical responses from the body and the architectural environment.
In looking at these contexts as a reference point for my work I am able to draw upon the unique
properties of vibration within music experience, such as its strong physical aspects, and tonal/
rhythmical qualities. I will investigate how vibration in these contexts can be rearticulated and
abstracted in composition. A focus will be on the natural processes of abstraction that occur when
music passes through a building and creates audible vibration; and how the resultant sound can
shift from being musical, to either unfamiliar or registered as environmental in nature.
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Appendix D
3.3 WHY? Rationale for program:
This research will present a range of composition and installation approaches to inform the
broader field of sound arts. Through the production of work focused on the physical in sound,
discourse will be encouraged to progress knowledge in this field, stimulating reflection within the
sound arts community on the significance of vibration in the experience of sound.
Audible Vibration
I feel that because of its subtle, physical role within a space, audible vibration can carry strong
associative weight to experiences of place and sound. I intend to explore these associative
connections and how they may be drawn upon in the creation of works.
The main association that I intend to explore is the perceptual connection between audible
vibration and the low frequency sound that has stimulated it. I am interested in how, through
composition, I can express vibration perception as falling within a continuum, with its character
changing as low frequency sound and the intensity of vibration increases. This range includes
vibration that is barely noticed, to vibration being a related part of low frequency sound (such
as a car stereo causing the rattling of the dashboard or doors, which act “responsively” and may
feel like an aspect of the music itself), to being independent, contrasting or discordant sound
(for example, vibration of a bedroom window transforming otherwise innocuous ambient low
frequency sound into something that feels physically present or even intrusive).
I perceive these types of connections to be largely integrated and subconscious aspects of
experience. Given the way they are experienced, I believe that these interactions between sound
and space offer strong potential for compositional exploration. By drawing upon different
characteristics of audible vibration, I hope to trigger the potential subconscious points of
reference they have to an audience’s experience of sound and encourage reflection on the way a
space responds to vibration energy.
Felt Vibration
Physical sensation in musical contexts provides a strong and evocative sensory foundation from
which I can investigate the dialogue between hearing and sensation, and how physical vibration
can augment the experience of sound. Being so strongly tied into particular experiences of music,
I am interested to see how these physical aspects can be reinterpreted outside of their original
contexts.
To develop this enquiry, I am interested in scientific research that looks at the general perception
of combined sound and vibration. Such studies will help me to better understand how people may
respond to vibration and to develop composition for the new medium of vibration technology.
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Appendix D
For example, in previous testing (SIAL, 2004) I found that where heard sound and vibration had
similar properties (such shared timing between felt and heard sound and overlap in tones between
the two senses), people found vibration and hearing to be mostly integrated and that the vibration
changed the way in which the overall sound was perceived, making it more immediate or intense.
Conversely, when vibration was tonally very different to the sound, people felt like they were not
connected and that the experience was disconcerting.
I aim to integrate ideas about sound/vibration perception in the creation of installation works,
using vibration in musical contexts as a primary point of reference. This research aims to explore
the points where vibration is integrated into the experience of sound in a space and the crossovers
between vibration that is heard and vibration that is experienced physically. The work will
enable me to evoke the experience of these aspects of sound in space and reveal (and potentially
manipulate) the peculiar relationships between our physical and auditory senses.
3.4 HOW? Methods:
Key project components are described below.
Mid to late 07:
- Construction of the tactile system (floor): involves steel fabrication and installation of its
wooden top. A variety of installation options will be experimented with, such as placement of
bolts and vibration absorption.
- Developing software for the floor: involves a combination of equalisation, filtering, timing
offsets (delays) and compression. This will be trialed in various software, including max/MSP
and Logic.
- Environmental recordings: Involves recording material from the areas around music venues
and other environmental sources of low frequency sound, including traffic and mechanical
sounds.
- Test and record material for space excitation: Using recorded and synthesised material to
stimulate vibrations in chosen spaces. Recordings will be made in two to three sites, using
musical low frequency material, abstracted to focus on environmental effects from the
sound.
Late 07 to late 08:
- Develop material for tactile system: audible and felt: Using gathered and new material to
explore the use of the tactile system as an instrument. Focusing on the types of sounds that
work with the tactile system, and the ways the system can be manipulated or “played”.
- Composition drawing upon audible vibration: Exploring ways in which recorded material
from the tactile system can be used in broader composition, and how the tactile system as
“felt” vibration device may work with “audible” vibration as played through loudspeakers.
May incorporate other sounds and recordings, other than those from the tactile system.
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Appendix D
Mid to late 08:
- Trial Performance: Presentation and audience evaluation within a space such as the RMIT
media arts theatrette. To seek feedback from peers about how the tactile system may work as
a life instrument, and how composed and improvised material work together artistically.
- Trial installation: Presentation within a student or other local artspace. Envisage a small
room, use of the tactile system with loudspeakers, combining tactile and audible vibration in
an integrated experience.
End 08:
- Final outcome: live or installation: To be informed from previous trials and evolution of
work. Seek to include tactile system in a primary way within the outcome.
Ongoing:
- Research: other artists, works etc exploring similar themes. This ongoing research includes
literature searches and listening to compositions in the fields of interest. See bibliography for
an initial list of works and artists.
Ongoing (peripheral):
- Max/MSP: Explore potential of Max/MSP software framework to generate sounds evocative
of audible vibration that can be more freely manipulated and shaped than recordings,
particularly for real time uses. I will continue to explore the viability of this option as a
peripheral aspect of the project.
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