Audio-visual equipment
The following advice should be read in conjunction with the Manage and Share Data section on the UK Data Archive web site.
Developing a qualitative research project involves important decisions about research goals and methodology.
Where a project involves recording interviews or discussions, decisions regarding recording
equipment are also important. The choice of appropriate kit can play a central role in gathering usable and suitable
research data. Initially a researcher should think about:
- the level of sound or picture quality needed
- the budget available for equipment and related consumables
- how quickly the technology being used will become redundant
- whether consent is in place to allow fullest use of recordings
- how the data created will be used
- whether data or information not allowed by consent can be excluded from recording
- whether the equipment will be simple to operate in the field
Audio recording
Taking steps to create audio recordings of good quality increases their usefulness to the research project. Poor
quality sound may not only offend the person being interviewed but also the researcher who realises sections of an interview are
indistinct, off-mike, or make sense only when used with additional interview notes. Good quality sound recordings should prevent
mis-transcription as well as reducing the chance of sections of an interview remaining untranscribed due to poor sound quality. Although
some recording equipment can be expensive it is a good investment if it is to be used time and again during a project, or even again on future projects.
Advice is provided here on the key issues surrounding creating good quality recordings in the field. See Audio-visual equipment: further reading for links to a selection of
other web sites offering additional advice on digital recording.
Microphones
The use of a microphone is the starting point of any recording. Good, or at least reasonable recordings, are dependent on a good quality microphone.
As a rule built-in microphones do not give good results. When choosing a microphone the situation in which it will be used should be considered.
For example, projects based on a series of interviews in potentially noisy situations may best suit a unidirectional microphone.
These are most sensitive to sound arriving from one particular direction and less sensitive to other directions. Pointing such a microphone
towards the subject will pick up all their sound but not that from other directions. If it is anticipated
that this is not going to be a problem, or if recordings of group discussions are expected to feature prominently,
an omnidirectional microphone (one that records sound equally from all directions) would be best.
The second option is whether to choose a mono or stereo microphone. In most cases researchers will not need the added
benefit of a stereo recording. As such microphones are also more expensive the assumption here is that a mono microphone
will be most suitable. A good uni-directional (or cardioid) microphone is the Shure SM58 or the Sennheiser MD-46. A popular
omnidirectional field microphone is the Electro-Voice 635A, which has been used in news gathering for decades. An
alternative is the Shure VP64A or the Audio Technica AT804. As hand microphones, all these will need to be used in
conjunction with a microphone stand. Another option is a clip-on (lavalier) microphone. These generally produce a
lower quality recording and have additional problems such as picking up the rustle of clothing. Even so, when used well
they can be less intrusive than a larger field microphone. Examples are the Shure WL93 and the AKG C 417 PP.
Cost is certainly a factor in deciding which microphone to purchase - quality is generally related to cost.
Recording devices
Once microphones have been tested and a selection made the next step is to consider what equipment to use. Where possible avoid equipment
which has not been designed specifically for field recording. Whilst various types of dictaphones or personal music players - such as an iPod -
may be used to make an adequate recording, the quality will generally be compromised due to heavily compressed files or inflexible file
formats. Wherevever possible recorders designed specifically for making field recordings should be used. There are currently a number of options to consider.
Digital recorders
Using these machines, recordings are saved onto a hard drive in a fixed internal memory or on a separate memory card. Absence of moving parts means there are
none of the problems of recorder noise as there is with older analogue equipment. Recordings can be easily and directly
transferred from the recorder to PC. Transfer is instantaneous and not carried out in real time. This is useful if one has built up a large collection of
recordings. Ensure that the chosen machine can accept an external microphone, that it has an output socket and ideally has a sound level indicator.
Many recorders marketed as dictation machines, such as the Olympus DM-10 or Olympus DM-20, are said to be of good enough quality to use
as field recorders. Whilst this is not a view supported by the UK Data Archive, it is true that when coupled with a good quality external microphone these
recorders can usually achieve a reasonable fidelity of sound. However their dependence on the result of file compression will always be a major drawback. Recordings
using a compressed format or, worse still, a proprietary sound format, have a potentially shorter lifespan as technology moves on and supported formats change. This may be a problem for their long-term use.
Other solid state recorders have been developed for use in the field. These often have the added benefit of using uncompressed audio files - such as WAV - which is
preferable. Well-reviewed recorders include the Marantz PMD661 and the Fostex FR2-LE, which have been designed specifically for field recording. Unlike
analogue recordings, if some portion of the recording is damaged or corrupted, the whole sound file is affected - generally resulting in the file being lost. Therefore the
need for back-up copies is great. As the cost of the
technology falls and the size of the memory cards/storage rises solid state recorders will become an increasingly popular option.
Analogue audio-cassette recorders
Although these recording devices are in decline there is still a range of very good machines to choose from. Many university departments or community organisations will be equipped
with these. They are a well-established technology that has had time to show there are no major problems caused by long-term storage of the media (depending on storage
conditions). Usually a recording made twenty years ago is as straightforward to play back as one made last week.
The Marantz PMD222 portable cassette recorder represents the industry standard for analogue recorders - although this is now discontinued as an item to
purchase from new. Good quality recorders such as this are getting harder to find, but can be obtained second hand. Ensure that whatever is used can accept
an external microphone, that it has an output socket, Dolby noise reduction (Dolby B is standard) and ideally that it has a sound level indicator. The audio cassettes used
with the recorder should also be good quality. Normal (or ferric) tapes should be chosen from reputable manufacturers such as BASF, TDK, Maxell or Agfa. C60 tapes should
always be used, as C90s and C120s tend to be far less durable. Chromium dioxide and metal tape should also be avoided due to their unsuitability as a long-term
medium. Copying to another cassette at high speed is possible if you have the right equipment, but these days most researchers will be interested in copying
to a PC. This will involve some process of digitisation and is usually done in real time.
Audio cassettes currently account for the majority of material currently preserved in archives of recorded materials. However they cannot offer the
same quality of recording as digital equipment being prone to background noise and tape hiss.
Digital mini-disc recorders
When it first came onto the market in the 1990s the MiniDisc was a very popular device with oral historians and field researchers looking for a portable and
effective way of creating quality recordings. MiniDiscs use recordable discs which are double-sided and very robust. The quality of recordings is much better
than audio cassette and almost close to compact disc. However there are drawbacks: the format is based on sound compression which involves the loss of some portion of the
recorded material. Unlike analogue recordings, if some portion of the recording is damaged or corrupted, the whole sound file is affected - generally resulting in the file being lost.
Again, if this type of equipment is used it is important to check that it accepts an external microphone and that it has a sound level indicator.
Manufacturers' concerns about the format being used to pirate commercially available music, led to recorders being manufactured with no line output.
This means transferring recordings, for example to a PC, is problematic. MiniDisc has its champions over the years but like DAT, it was a pioneering digital recording
technology that failed to establish itself.
Archiving audio recordings
Digital recording is quickly replacing analogue. Digital hardware produces excellent recordings but file formats will always be changing. Long-term reliability
and accessibility are key difference between analogue and digital recordings. These are significant differences and should be fully appreciated.
If analogue material is damaged, some portion will still be playable and listenable in most cases - assuming hardware is available to play it.
Digital files which are corrupted or in outdated formats will be unplayable in their totality. Thus, the longevity of particular file formats is a key issue.
Digital media may outperform analogue tape for fidelity of sound, but they also impose another set of technical decisions.
If handled badly these can seriously affect the quality of recordings. The growing popularity of CAQDAS data analysis will doubtless encourage many researchers to create and work with pure digital material. In such cases it is important to ensure that a procedure for creating archival back-up copies is adopted. These should use uncompressed files and -
crucially - be reviewed periodically to ensure file formats have not become redundant. One constant concern should be that
research created today will still be available to the researcher at a future time in their career.
Furthermore audio recordings, like other digital data such as video recordings, should be seen as potentially archivable material that may be protected by the same restrictions and safeguards as text. Generally, assumptions that all such data is inherently sensitive, confidential or difficult to share are wrong.
For further advice or specific queries, contact
acquisitions@esds.ac.uk.
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