Digital equipment guidelines
Oral History
British Library Sound Archive
February 2010
WeThese guidelines reflect current practice in the British Library’s oral history
department. We update them as soon as we receive any new information about
equipment or when we change our procedures. For the most up to date set of
guidelines please contact us.
1. Oral history fieldwork equipment
2. Memory cards
3. Uploading and saving digital recordings
4. Listening/playback software
5. Specification for computer hardware for processing digital files
6. Archiving and storing digital audio files
6.1 CDRs and DVDs: general pointers
6.2 Audio CDs and data CDs
6.3 DVD-Rs
6.4 Sourcing CD-Rs and DVD-Rs
6.5 Archival storage on hard disc
7. Computer software programmes to burn CDs and DVDs
8. Procedure for interviewers working remotely from the storage/archive site
9. Digital editing
10. Retrospective digitisation of older audio formats
11. Cataloguing
12. Transcription software
13. Video
14. Further references
15. Other useful websites
Oral History, British Library Sound Archive, 96 Euston Road, London NW1 2DB
Tel 020 7412 7404/7405/7406 Email or
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British Library Sound Archive
February 2010
1. Oral history fieldwork equipment
In recent years ‘solid state’ digital recorders have replaced the analogue recorders (such as
audio cassettes) and older digital formats (like minidisc) that many oral historians used.
Called ‘solid state’ because they have no moving parts and record audio directly to a
memory card, there is a bewildering range of makes, models and formats available. There
are also a number of recorders with built-in hard-drive memory, often in addition to the
memory card. Some recorders use ‘proprietary’ or compressed digital formats which are
not internationally-recognised and may not be future-proof: these should be avoided,
especially as some will record poor quality audio. Compressed files can also audibly
degrade when they are converted to another format.
At the British Library (BL) we have been using the Marantz PMD660 solid state flash card
recorder. This is a mid-range compact professional model which has proved reliable and
easy-to-use. With it we use a 2GB Compact Flash card (CF card) and record PCM WAV (or
.wav) files at 48kHz/16bit (giving you c.3hrs stereo audio per 2GB flash card). As we want
to archive high quality recordings to recognised standards, we record in PCM .wav
format, not MP3 or other compressed format, so that all of the data from the recording is
stored. Recording at 44.1kHz 16 bit also gives a good standard of recording.
Recently the Marantz PMD660 was discontinued and replaced by the PMD661, which uses
a Secure Digital card (SD card). Whilst we have limited fieldwork experience of this new
model, British Library Sound Archive engineers have tested the machine and are able to
recommend it.
Although the BL has recently purchased several PMD661s, there are several cheaper (and
more expensive) makes and models on the market which might be better suited to
particular projects and budgets.
Whichever model of digital recorder you choose it should have the following features:
Be able to record in stereo using two external microphones (preferably with
professional XLR sockets)
Be able to record uncompressed PCM WAV (or .wav) files to a minimum of at 44.1kHz
16 bit and/or 48kHz 16bit. This is a good standard of recording quality using a widelyrecognised format.
Have a USB2 connection to allow the recorded files to be uploaded easily to a
computer for renaming, security copying and long-term storage (as an additional
method to uploading the audio to a computer by placing the CF or SD card in a card
reader attached to the PC)
Be capable of being powered by both rechargeable batteries and mains supply.
We currently use the Audio-Technica Pro 70 Lapel Microphone, which is a cardioid
directional microphone. For one-to-one interviews we record in stereo, clipping one mike
on the interviewer and one on the interviewee. These microphones use phantom power
from the recorder which means that they don’t require their own batteries and, as they are
shielded, you can use mains power supply for the recorder, without mains interference,
although we recommend using back-up Duracell AA batteries as the recorder has no
rechargeable battery and an unexpected power-down can result in loss of data. If you
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February 2010
purchase these microphones ensure that your recorder can provide phantom power. Full
specifications, prices and details can be found at (who can
also advise on other fieldwork recorders including a laptop recording option; on other
microphones, eg for group work; and transcription software) and .
2. Memory cards
Memory cards come in a variety of formats and memory capacity. The Marantz PMD660
uses Compact Flash cards (CF), whilst the PMD661 uses Secure Digital (SD) cards. Each
make and batch of cards can have slight variations in reliability. Costs vary as does the
speed that data is written to the card. We have had one instance where one batch of flash
cards was incompatible with the PMD660 – the word ‘unformat’ appeared on the screen
and the PMD would not respond until the card was removed from the machine. We
suggest that you buy one sample CF or SD card and test its compatibility before buying a
whole batch.
Marantz recommend the following flash cards: LEXAR, PNY, VIKING, IBM and
HITACHI. At the BL we have used other brands and experienced very few problems,
although on rare occasions the data has not written to the flash card. If this happens and it
appears that there is no data on the card it might be that the ‘table of contents’ that
identifies the data has been corrupted. In such cases all is not (always!) lost and specialist
audio technicians can sometimes retrieve the audio.
It is now increasingly difficult to source 2GB CF cards and SD cards: 4GB cards are usually
the smallest size available. The BL Sound Archive Technical Section has advised against
recording digital audio WAV files that exceed 2GB in size. This is partly for data security
because if the card has a fault (which is rare!) then less material will be at risk of
corruption. For files over 2GB there is also potential alteration in the type of digital file
created, which may make the file difficult to open in digital editing programmes and has
implications for the security of the audio file’s long-term preservation.
In order to avoid this issue, we are instructing our interviewers when using a CF or SD
card over 2GB to ensure that any single track does not exceed the following lengths, which
are equivalent to just under 2GB of data:
44.1 kHz 16 bit stereo recording
Maximum advisable length of track: 3hr
48 kHz, 16 bit stereo recording
Maximum advisable length of track: 2hr 50 mins
48 kHz, 24 bit stereo recording
Maximum advisable length of track: 1hr 50 mins
3. Uploading and saving digital recordings
Once the memory card contains data to archive we upload the .wav files to computer (we
use a PC but a MAC can equally be used) via the USB port in the recorder or (better) via a
card reader plugged into USB2 port on the PC. We upload, rename, and back up to
external computer hard-drive, then make an additional copy as an MP3 for access
purposes. It’s also possible at this stage to make a further copy (say for an interviewee or
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February 2010
transcriber) onto a DVD or CDR, though neither should be regarded as an archival
version. Then (and only then) it's possible to ‘reformat’ (ie wipe) the memory card ready
for the next recording. It's worth buying a few spare memory cards and/or a laptop or a
portable external hard-drive to back-up for long field-trips away from base.
On a day-to-day basis our interviewers and transcribers use the MP3 files (rather than the
.wav files) when making content summaries and transcribing. If you do not have a digital
editing programme, such as Sound Forge or Wavelab (see below), there are two
programmes that can be downloaded free from the internet which can batch convert .wavs
to MP3:
 WinLAME then choose:
winLAME prerelease 4 (Windows Installer) at Sourceforge.
 free-source audio editing programme Audacity
can also batch convert when used in conjunction with WinLAME
When making MP3 copies, we use this specification: 64kbps constant bit rate.
4. Listening/playback software
At the British Library we have found Media Player Classic the most versatile for reading a
wide range of digital recordings. This is not the same programme as Windows Media
Player. The programme can be downloaded free via the internet from
A good player for recordings made at 24 bit and/or at 96 kHz, is the VLC player, free to
download at The VLC media player is a free-to
download open source media player and multimedia framework written by the VideoLAN
project. VLC stands for VideoLan Client and the symbol for VLC is an orange and white
striped traffic cone.
5. Specification for computer hardware for processing digital files
As audio files can take up a lot of memory space it is important to use the optimum
specification computer hardware and software for most effective and reliable copying,
data transfer and editing. A computer with lower specifications may adequately process
digital files, but the PC may run slower and store less data.
RAM – 512MB minimum, 1GB recommended
Operating System – Windows XP or later versions. Other systems might work, but
may run into compatibility problems at the archive/storage site.
Processor – Any computer with a processor at least 1GHz is acceptable. Beware – the
numbers quoted with processors can be misleading. A 2GHz Pentium M processor is
faster than a 1GHz Pentium M processor, but not necessarily faster than a 1.6GHz Intel
Core Duo.
DVD burners – Burning to DVDs and CDs is possible with a Plextor PX 760 drive,
which can be bought as an internal or external drive (external is more expensive). We
have found that Nero software is better than the software that is usually bundled with
a DVD drive (see below). Many Plextor drives come with Nero software.
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February 2010
6. Archiving and storing digital audio files
Audio files can be stored on a variety of different digital media. At the BL we have
recently moved away from CDR and DVD-R storage to computer hard-drive and massstorage solutions for long-term preservation, partly as we have experienced frequent
data errors and data loss with many optical discs such as DVD-R and CD-R. For many
projects external hard-drives will now be an affordable option for archival storage and
this is what we would recommend. We list below some useful advice regarding transfer
to CDR and DVD-R (suitable for temporary storage and for donor/playback copies) and
storage on external hard drives (for long-term archival storage).
6.1 CDRs and DVDs: general pointers
Avoid cheap CD-R or DVD blanks that can be bought for a few pence each. They are
of low quality and may well not last for very long.
Avoid using CD-RW or DVD-RW. Re-writeable discs are unlikely to be as compatible
on different machines as CD-R or DVD-R.
It is important to make back-up and/or playback copies on a different brand of CD-R
or DVD-R to the Master. This is to lessen the risk in case one batch or brand of disc is
found to have problems.
When labelling a Master CD/DVD make sure there is as little writing or printing as
possible: and ensure you use no adhesive labels, no pencils or hard pens: only felt pens
which are water rather than solvent-based to prevent any possible damage to the data
as the CD/DVD ages.
6.2 Audio CDs and data CDs:
CDs can be burned to play as audio CDs in an ordinary CD player or as data CDs which
contain image, sound or other data files. Any CD burning software should give you the
option of burning data or audio CDs.
Audio CDs
 Contain digital sound at 44.1kHz and 16 bit at maximum of 74 minutes duration
 Can be played on an ordinary CD player and/or computer
Data CD-Rs
A CD-R can store any type of data. It can store sound files of any type, such as .wav or
 If you want to burn stereo PCM .wav files at 48kHz 16-bit, a CD can store data which
is less than 74 minutes duration
 If you want to burn mono recording at 48kHz 16-bit PCM WAV, a CD can store
recordings of approximately 2 hours duration
 You can store a large number of MP3 files on a CD
6.3 DVD-Rs:
A DVD-R can also store any type of data, including sound files such as WAV or MP3
 If you want to burn stereo PCM WAV files at 48kHz 16-bit, a DVD-R can store data up
to approximately seven hours duration
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February 2010
BUT beware there are several types of DVD-R and there are archival implications about
how much data you burn to a DVD-R.
 Storing MP3s on disc
A CD-R or DVD-R can store many more MP3 files than PCM WAV files. However we
advise that you do not record in MP3 format, but use MP3 copies of WAV files for
playback copies.
6.4 Sourcing CD-Rs and DVD-Rs:
Warning!: Different manufacturers produce discs of different grades but a similar physical
specification. The differences are not always obvious from the description of the discs, and
they can be changed over time with no indication of the fact. Any given brand and type
might refer to multiple products of differing quality! Also compatibility between disc and
burner is crucial, and impossible to reliably predict or measure without some form of
testing. Similarly, choosing the most appropriate burn speed is crucial, and will again
depend on the particular disc and burner. In short this is a highly complex area which is
impossible to address adequately for all contexts. Far better and safer is to regard CD-Rs
and DVD-Rs as convenient playback copies and to archive your .wav originals onto
computer hard-drive. But if you do plan to use optical discs refer to Kevin Bradley’s
authorative paper online at
The British Library Sound Archive formerly used the MAM-E (Mitsui Advanced Media
Europe) gold CD-R (80 minutes at CD quality). However, MAM-E have now gone out of
business. Stanley Productions ( can supply MAM-A
(Mitsui Advanced Media America: a different company than MAM-E) products such as
gold CDRs and DVD-Rs which have been regarded as more reliable carriers of audio, but
these have not been tested by the British Library.
We also use a Taiyo Yuden silver CD-R that is 74 minutes – not the 80 minute disc – (from For DVD blanks we use the Taiyo Yuden DVD-R
(single layer, 4.7GB capacity). To source other silver CD-R or DVD-Rs try contacting the
6.5 Storage on hard disc:
Hard disc drives are manufactured to last only a few years. In practice, they might last
longer, but the notion of a single individual drive as a reliable long-term store is a nonstarter.
However, drives can successfully be used for long-term storage by replicating data
across more than one drive.
The particular drive model is less important than the strategy of using different brands
of drive in order to diminish the risk of simultaneous drive failures.
The simplest system is to manually mirror (replicate) data across at least one other
drive, and store the replica(s) in different locations.
As well as establishing a regular (daily) back-up routine it is worth using a system that
regularly checks each disc for integrity, sector errors etc, as well as verifying that data
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February 2010
copying is accurate. RAID systems are becoming cheaper and can be used to replicate
and check data across several disc drives, and automate the process of restoring data
automatically when a particular drive fails (
Some systems use RAIDs coupled with off-line backup on optical disc or on tape
drives (LTO etc) as extra security. The BL uses this kind of mass storage system
(known in the BL as the ‘Digital Library System’) but multiple external hard-drives are
likely to be a more viable and affordable option for most projects.
7. Computer software programmes to burn CDs and DVDs
We use Nero burning software: Nero Burning Rom 7 is available at
We use the following settings when burning a CD or DVD with Nero, which ensure
maximum compatibility with other computers. Check these settings on the tabbed
dialogue box:
Multisession: select no multisession
Data mode should read Mode 1
File system: select ISO 9660 only
File name length (ISO): select Max of 31 chars (Level 2)
Character set (ISO): select ISO 9660 (standard ISO CD-ROM)
Action: tick Write
tick Finalize CD
Write speed: select x32 (if using for playback copies); select x4 or x 8 [if using
for archival purposes, but note that this is no longer recommended – see points
6 and 6.5 above]
Write method: select Disc at once
Number of copies: set to 1 and tick Burn-Proof
Multisession: select ‘no multisession’
filename length: select ‘max of 31 characters’
character set: ISO 9660
Label: ignore this
Dates: File dates: select ‘use date and time from original file’.
Burn: action – write
finalise DVD (this may be greyed out)
Disc at Once (this may be greyed out)
Write Speed: x4 [if using for archival purposes, but note that this is no longer
recommended – see point 6 and 6.5 above]
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February 2010
8. Procedure for interviewers working remotely from the storage/archive site
Any interviewer who will be dealing with original .wav files must ensure that their
computer has the software and memory space to process .wav files and that they can
burn both DVDs and CDs.
a. Interviewer records on memory cards as usual.
b. After each session, interviewer uploads the material onto a secure and virus free
computer. DO NOT WIPE (or ‘reformat’) the original memory card.
c. Generate a checksum for each audio file (go to for a simple
and free application to do this). Checksums are extra blocks of data which are
stored alongside the audio data and can be checked after transfers to ensure the
integrity of the data is unchanged.
d. Burn the .wav and checksum files to archive standard DVD, using the software and
specifications explained above.
e. To make a copy for summarising, batch convert the .wav files to MP3 and store on
the computer and/or burn to CD – see above.
f. Send the DVD of .wav files to the archive/storage site. In our opinion, sending
memory cards through the post is too risky. The cards are small, easy to mislay
and, if lost in the post, the only copy of the interview is lost.
g. The staff at the archive/storage site will then check that the DVD can be opened
and, using the checksums, that each .wav file is accessible and uncorrupted.
h. Once the interviewer has received confirmation that all the .wav files have been
safely received and successfully opened, the memory card be erased/reformatted.
Alternatively, you could upload material from memory cards onto an external hard drive.
After carefully checking that the .wav files have been successfully uploaded to the external
hard drive, the memory cards can be erased. You can then upload .wav files from the
external hard drive onto a computer and burn them to DVD. However, the .wav files
should not be wiped from the external hard drive until the staff at the archive/storage site
have made sure the files on the DVDs are accessible and uncorrupted.
9. Digital editing
There are a large number of software packages suitable for editing digital audio on PCs
(and macs), but for basic speech editing Audacity, a free piece of open-source software
downloadable from, is perfectly adequate and
For more sophisticated editing (perhaps involving music and effects) requiring greater
functionality, such as filtering and multitracking, other packages should be considered.
The BL uses Wavelab. 6
Wavelab Studio 6 is c.£250
Also worth considering are
 Adobe Audition ( at around £225
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February 2010
Sound Forge
( at around
For a cheaper alternatives try:
 Sound Forge Studio ( at around
 Wavelab Essential 6
abessential6.html) at about £85, to buy as a CD pack or to download
The basics of audio editing are easy to learn and the British Library in conjunction with the
Oral History Society runs a one-day digital editing training course.
10. Retrospective digitisation of older audio formats
Depending on the material to be digitised and the resources available, it may often make
sense to employ specialist contractors to carry out digitisation, particularly if it involves
digitising open-reel tapes, discs or other older formats; or if there is any evident
degradation. We can provide a contact list on request.
Until recently analogue audio cassettes were routinely used by oral historians. This format
is now virtually obsolete but there is little evidence that the cassettes themselves will
degrade if kept in ideal conditions (British Standard 5454 June 2000 suggests 19ºC ± 1ºC,
40% relative humidity ± 5%). Nonetheless a programme of assessment and progressive
digitisation is recommended. Another, digital, format in use until recently was Minidisc
(MD) which has always had the disadvantage that it uses a proprietary compressed
format. This is now also rapidly becoming obsolescent. It is therefore advisable to copy
their contents to a more secure digital medium (with appropriate back-ups).
To digitise small batches of cassettes a basic digitisation kit might comprise:
 a good quality cassette deck capable of decoding any noise reduction used in recording
the cassettes (such as Dolby B or dbx) and with adjustable azimuth.
 a PC with a good quality sound card and in particular good A-D converters, and a
reasonably fast PC or Mac.
 editing software such as Sound Forge, Adobe Audition, Wavelab or Audacity (details
It is extremely important to save the audio in PCM .wav files, rather than a compressed
format such as mp3. Use the PC to create and save .wav files onto computer hard drives,
sampling at 44.1 kHz or 48 kHz at 16 or 24 bits, depending on the quality of the originals.
If memory space allows, a higher specification might be considered.
The benefit of using a PC is that it's easier to do the transfer via a digital editor to allow for
minor editing if appropriate, such as splitting and joining tracks, and adjusting levels. You
can then use a batch converter to convert all the .wavs to mp3 files for access and for
transcribers' copies, and preserve at least two copies of every .wav file, ideally on at least
two brands of medium, stored in different locations (see 6.5 above).
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February 2010
11. Cataloguing
The British Library Sound Archive currently uses SirsiDynix Symphony (formerly known
as Unicorn) collection management software to run the Sound Archive online catalogue
( Data is held in an internal (and non-standard) MARC format with
many additional fields to cope with (a) the breadth of the collections, and (b) technical and
preservation metadata.
For partnership projects with the BL Sound Archive we can provide a customised Excel
spreadsheet for collecting standardised data for later conversion to the Sound Archive
online catalogue.
12. Transcription software
Our freelance transcribers are currently using Express Scribe Transcription Playback
software which is a free download from This is
controllable via ‘hot keys’ on the keyboard and/or via a remote footpedal. Alternative
software includes Start Stop, details at
Contact us if you wish to see a copy of our transcription guidelines.
13. Video
The British Library Oral History department does not currently carry out video fieldwork,
although we run, in conjunction with the Oral History Society, a one-day oral history and
video training course. However, we have found the following information useful :
 Filming video oral histories
These two sites offer online training packages about using video for interviews:
For advice on filming try:
 Archiving and preserving video formats
The BL has published some general guidelines on video preservation, for its Endangered
Archives programme, which is online at
Many projects use miniDV video format, which is a digital medium. Copying to other
formats could result in a loss of data, so one option archivally would be to copy from
miniDV to a second miniDV tape, simply for the security of having more than one copy.
You can copy to a higher grade tape format, DigiBeta being a standard, but the costs then
become very high. Ideally, you might want to have the recordings copied as
uncompressed avi files onto a hard drive. Further migration to MPEG-4 or JPEG2000 (an
emerging standard) would be considered best for preservation.
There is a handy guide to preservation and migration options for various video media at: .
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British Library Sound Archive
February 2010
Some of the information derives from a lengthy report, (especially pp. 60-63). There is helpful information in plain language on the Keep
Moving Images site (designed for video artists but with good general principles) at More technical, but often with the answer you’re looking for, is DV
information page at Another, somewhat technical site, is A little less daunting is
14. Further references
Dietrich Schüller’s summary overview of the main audio formats and their particular
features is a good introduction, available to download at
Kevin Bradley’s Guidelines on the production and preservation of digital audio objects (2004),
published by the International Association of Sound and Audiovisual Archives (IASA TC04) and The safeguarding of the audio heritage: ethics, principles and preservation strategy (IASA,
third edition 2006, TC-03) are essential reading: details at
A leaflet published by the National Preservation Office “Basic Preservation Guidelines for
Library and Archive Collections” can be downloaded at
A useful report about analogue to digital transfer, commissioned by the US-based
National Recording Preservation Board at the Library of Congress, entitled Capturing
Analog Sound for Digital Preservation: Report of a Roundtable Discussion of Best Practices for
Transferring Analog Discs and Tapes (June 2006) is available online at:
A report, “Risks Associated with the Use of Recordable CDs and DVDs as Reliable Storage
Media in Archival Collections - Strategies and Alternatives” by Kevin Bradley was
published online by UNESCO, and can be found at: Fred Byers’ 2003 report
“Care and handling of CDs and DVDs: A Guide for Librarians and Archivists” is available
online at: A leaflet published
by the National Preservation Office “Caring for CDs and DVDs” can be downloaded at
The IASA Cataloguing rules can be consulted for advanced advice on aspects of
description of audiovisual materials. It can be purchased in printed form or viewed online at: For specific advice on cataloguing oral history consult Marion
Matters, Oral History Cataloging Manual, Society of American Archivists, 1995; and go to for examples of oral history catalogue records.
15. Other useful websites
Oral History Society: Getting Started
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British Library Sound Archive
February 2010
Oral History Society: Is your oral history legal and ethical?
Oral History Society: Training Courses
Vermont Folklife Center audio field recording equipment guide
Oral History Association (USA) technology and equipment advice pages
Oral History, British Library Sound Archive, 96 Euston Road, London NW1 2DB
Tel 020 7412 7404 /7405/7406 Email or
© 2010
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