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- Equipment
- Technique
- Software
- Online resources for
digital recording
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The Vermont Folklife Center’s Digital
Audio Field Recording Equipment Guide is an excellent
online guide to digital audio recording equipment.
Although most of this section deals with digital
audio recording, a good resource on digital video
recording is the single-channel video sections of
Electronic Arts Intermix’s Online
Resource Guide for Exhibiting, Collecting, and Preserving
Media Art.
Below is a sample equipment start-up list for recording
and transcribing digital audio:
- Marantz PMD 660 ($500) or 670 ($700) Digital
recorder Note: the 660 is perfectly
adequate for most oral history projects, but the
670 has better quality ¼” RCA jacks
instead of 1/8” mini jacks, thus making it
a better choice if you intend to use it for analog-to-digital
conversion instead of a computer.
- Omni-directional or cardioid condenser microphone
(price varies) Note: For Marantz
recorders, the manufacturer recommends using a
condenser rather than dynamic microphone. Some
microphones also require phantom power from the
recorder, and may feature a 1/8”, ¼”,
or XLR (3-pin) connector. Be sure that the type
of microphone you purchase is compatible with your
recorder and check whether the microphone includes
the appropriate connecting cabling or adapters.
- XLR microphone cable ($20)
- Tabletop microphone stand ($20)
- 100 pack MAM-A (Mitsui) gold archival CD-R discs
($137)
- Lexar 2-gigabyte or larger compact flash card
(price varies)
- USB-connection transcription foot pedal ($80)
See also the equipment budget in Analog-to-digital
conversion |
Most oral historians record with
one microphone placed between themselves and the interviewee,
but some insist on using separate microphones for both
interviewer and interviewee to reflect the two-way
nature of the interview. When using a single microphone,
place the microphone between the interviewer and interviewee,
and record the audio as L/R mono (single channel).
When using two microphones, place one in front of the
interviewee and one in front of the interviewer to
record two-channel audio in stereo. Remember that the
further away the microphone is from the speaker, the
more ambient noise is picked up. Also keep in mind
that two-channel audio creates a file twice as large
as single-channel for the same recording time.
Recording specifications should be set as follows:
- file type--uncompressed PCM (pulse coded modulation)
.wav or .bwf (broadcast wave file) format
- bit depth—16bits
- sample frequency--44.1MHz
This yields CD-quality audio appropriate for archival
and broadcast use. At these settings, one hour of
recording time creates a file of approximately 300MB.
A 1-GB compact flash card can hold approximately
3 hours of recording time in mono. For a chart of
recording times and file sizes for various digital
audio file formats and sampling rates, click
here.
For more information see Recommended
digital recording settings and file formats.
To ensure good sound quality and recording levels,
be sure to do a sound check before each interview.
After placing the microphone(s), have the interviewee
record a few seconds of sound (such as reciting the
Pledge of Allegiance), then play it back. Watch the
recording level meter. The sound levels should peak
during louder moments toward the right/higher end
of the meter (shown in red on some meters), but not
all the way to the highest level. If the meter stays
too low, the recorded sound will be difficult to
hear. If the level is too high (the meter stays at
the highest setting), the recorded sound will be
distorted or clipped as the sound exceeds the recorder's
ability to capture it. Adjust the recording level
until the meter shows sound peaking but not maxing
out in the high end of the meter.
Once the interview is finished, be sure to hit "stop" to
end the track. The audio file can then be downloaded
from the recorder to a computer hard drive via either
an I/O cable connected to the USB port or by removing
the compact flash card (or other storage media) and
inserting it into the corresponding computer port.
Most newer computers feature slots for a variety
of media; if yours doesn't, then either use an external
card reader or the I/O cable.
Once the file is downloaded to the computer, you
will need to name it. See "Preservation:
Guidelines for naming files."
It is possible to record interviews cheaply and easily
in .mp3 format with an iPod, and sound quality can
be enhanced with a good quality microphone. As the
storage capacity and technology continues to improve,
so will the sound quality, though at present it is
still inferior to the equipment described above, especially
since recordings are in .mp3 rather than the higher
quality .wav format. For an oral history project on
a tight budget, it is worth reading the USF Oral History
Program's guide, "Recording
with iPods." |
For transcription, ExpressScribe
software is discussed in the Transcribing
Interviews: Tools section of this site.
Sound editing software has a variety of applications
for digital oral history, and can be used for correcting
sound problems such as removing unwanted background
noise or amplifying audio with low recording levels.
Audio recorded in mono can be split into stereo tracks
if desired. Sound editing software also enables users
to manipulate the “raw material” of a full-length
interview and produce streamlined, broadcast-ready
versions that eliminate false starts and irrelevant
digressions. An audio file can be edited with a visual
linear representation of the sound which facilitates
cutting and pasting the audio with precision. The final
edited file can then be exported in a variety of formats,
including .wav, .mp3 and Ogg Vorbis. The derived files
are ready to post to the web as streaming audio or
podcasts, or to be used in other forms of electronic
publication such as CDs and DVDs. When creating listening
copies for patrons and interviewees, oral history programs
generally burn CDs using derived .mp3 or Real Audio
files. If the original audio was edited to improve
sound quality, the edited version should be used for
listening copies, unless a patron specifically requests
an unedited version.
Audacity is
free, open-source software for analog-to-digital conversion
and sound editing. It has a bit of a learning curve,
but is adequately documented. If there is a budget
to purchase software, the most widely used commercial
sound editing program is Sony’s
Sound Forge,
$60. Other recommended software programs include Digidesign
Pro Tools (included with Digidesign mixing boards
and other products) and Samplitude.
If you plan to do large amounts of sound editing, you
may want to invest in a mixing board, discussed in
Analog-to-digital
conversion. Vertov is
a useful media annotating tool that can be used for
analyzing oral history audio and video files, available
as an annotating plugin for Zotero (http://zotero.org),
a free, easy-to-use Firefox extension to help you collect,
manage, and cite your research sources. Vertov allows
you to cut video and audio files into clips, annotate
the clips, and integrate your annotations with other
research sources and notes stored in Zotero. It is
produced by the Concordia
Digital History Lab at Concordia
University, Montreal, and was developed by Stuart Thiel.
For more details on sound editing for oral history,
see the Vermont Folklife Center’s Digital
Editing of Field Audio. |
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