> I want to understand the basics of the various technologies that are work=
ing in the background - albeit now in a palm sized machine and also learn t=
he dos and don'ts of field craft.
>
> I understand that Bernie Krause has a very good book on the subject (whic=
h I am in the process of acquiring.
Sudipto,
Bernie is the master and he is on this email list which is fortunate for us=
when he has time to write.
> Not that I want to tamper with the sound or change it in any way but I am=
sure there is more to post processing than just push up the volume a bit.=
"Tamper" is the wrong word to use. Recording is an artificial process like=
photography, and the aim is to present the recording in a "packaged" form
just as we do with a photograph. You can't just present the sound as you
hear it, but you have to do some interpretation to make it sound "real"
starting of course by deciding on the beginning and end, avoiding passing
aircraft and so on.
As an example, recording thunder can be disappointing, but this is a specia=
l
case. The way to make it sound "real" is to let it overload on the loudest=
bits, but most digital recorders won't let you do this and a limiter kicks=
in. My pet hate is limiters and compressors which always sound artificial
and make the background sounds "pump" down and up. The trick is to record
low and to distort the peaks in post editing.
With wildlife sounds, you need to avoid distorting them by recording low.
How low you record depends on your system, but as long as the recorder nois=
e
is below the background and mic hiss, you are losing nothing. In the days o=
f
tape recording, we were fighting tape hiss and kept recording levels high,=
but the joy of digital recording is that you can often record
peaking as low as -18dB and lose nothing. It is worth testing this out with=
your setup.
The general rule is to present the edited recording as close as possible to=
what you heard with your ears. This is often not easy but it is the art of=
recording. For instance on playback, there may be a low frequency backgroun=
d
which interferes with the wildlife sound or is distracting. In this case, I=
use my judgement to make the recording sound more like what my ears heard,=
giving prominence to the wildlife sounds. This is similar to framing a
photograph or adjusting its tone values in order to reproduce what you saw=
with your eyes.
I have occasionally used a gentle noise reduction in the Audacity editor to=
reduce mic hiss in very quiet recordings. With this I use a HPF filter on
the noise sample. The justification is that I dind't hear mic hiss with my=
ears in the original location and provided that the wildlife sounds remain=
intact, I am reproducing the original sound experience. Another example is=
occasionally using a narrow notch filter to reduce a whine from a grain mil=
l
about a kilometre away from my woods. Also, with birdsong, I make no apolog=
y
for using a gentle bass roll-off, again to match the recording with reality=
.
For anyone with Audacity, I have many filter definitions on:
http://www.stowford.org/sounds/eqcurvesadd.txt
David Brinicombe
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