Syd Curtis wrote:
> Dan Dugan wrote:
>
>
>>From: Dan Dugan <>
>>Date: Thu, 24 Apr 2003 12:27:48 -0700
>>
>
>
>>I think it's entirely appropriate for threads discussing arcane
>>engineering issues and threads on which way to point the microphone
>>to co-exist on this forum. If it's above your level, pick up what you
>>can, ask questions, or go on to another message. There are always
>>people willing to explain to the newcomer.
>
>
> Much of the discussion - almost all of the engineering discussion - is above
> my level. But I like to watch from the sidelines. And after all, clicking
> on 'delete' does not take much time or effort, if something does not
> interest me.
>
> What I seem to have missed and which would interest me, is how and why
> scientific values of nature recordings are going to be compromised by
> apparent or real limitations in the recording equipment. Just how are the
> recordings going to be used, where such limitations are going to be a
> problem, considering what the environment does to the sound by the time it
> reaches the mic.
That's a question rarely addressed, though it's often quoted as a reason
for some piece of equipment. The truth is that, except for some precise
calibrated measurements, that require specialized equipment and are done
by only a few, virtually all science recording can be done well with
something as simple as a cheap cassette recorder or walkman MD. If that
recorder is in the right hands.
Casually made nature recording is not going to end up in that precise
measuring track. To think so is in error, and to justify equipment
choices on someday someone may want to measure the details just won't
wash. Casually made nature recording has value to science primarily to
document the existence of that species in that spot at that time. Not
much sound quality is necessary for that.
> I started recording in 1968, with guidance from the Division of Wildlife
> Research of Australia's CSIRO. It was an essential part of a research
> project on the vocal behaviour of lyrebirds. I couldn't afford a Nagra as
> favoured by CSIRO, but I managed to get satisfactory recordings with an open
> reel Uher. And BTW, I tested that same Uher last lyrebird season and 30+
> years on it still makes reasonable recordings if used to optimum effect in
> the field.
>
> Analysis of the recordings was carried out by CSIRO on a Kay Sonagraph. No
> personal computers in those days. The impression I got then (and I've seen
> no reason to change it), is that the environmental effects alter the sound
> far more than does any short-comings of the equipment if it is of at all
> reasonable standard. I recall CSIRO's lyrebird expert telling me that I'd
> be able to get quite satisfactory recordings with an analogue cassette
> recorder, provided I had a good mic., and of course, provided it was a
> recorder with manual level control.
>
> In '74, I took a small (relative to the Uher) National Panasonic cassette
> recorder to the top of Mt Barney, because it involved a very steep climb of
> about 4000 feet in elevation, and got satisfactory recordings of several
> bird species of particular interest to me, (and of a frog, Walter, because
> he was there). But I had a Sennheiser Shotgun mic.
>
> I guess that the Kay Sonagraph analysis of the sounds was markedly inferior
> to what you good folk are doing now in that direction, but it was good
> enough to indicate the very substantial degradation of the sound that
> occurred if I was recording from a distance with a parabola (or worse,
> without one!). Only when I could get my mic close to a lyrebird, say less
> than 2 m for an 'ordinary' mic., maybe 5 m for the shotgun, could I get
> 'clean' recordings that suggested the sound reaching the mic was pretty much
> the same as when it left the bird's beak.
I've used a Kay Sonagraph, that's what I first learned sonographs on,
back before you started recording by a 6 years or so. I don't know as
I'd say it was markedly inferior. We can get more detail out of the
computer derived sonograms, and color coding can give a better idea of
the sound levels, but either works. I am glad with how quick and clean
the process is now. I could not have visualized using it on all of every
single recording as I do now with sonograms. And having the sonogram
scroll by in realtime is truly magic.
It's all in viewpoint as far as degradation with distance. It's a
natural part of the environment, often contributes considerably to how a
call sounds. And often the animals are very well aware of the effects.
Only when doing sonograms does it matter much. Even there the modern,
higher resolution sonographs give us a good picture even of pretty
distant calls. As long as we don't have to have absolute sound levels of
each part for some study. Doing that sort of calibrated recording is
really outside of the general area of the nature recordist's group.
> I strongly endorse the advice already given for anyone wanting to start
> nature sound recording: get out there and start recording. Priority 1: the
> best mic you can afford. Then make sure you have a recording device that
> allows manual control of the recording level. Apart from that, the basic
> operating system doesn't matter all that much. You'll get a lot of
> satisfaction regardless. And you'll find you can improve your recordings
> more through experience and technique, than by chasing the ultimate in
> recording device.
That's about the size of it. There is this tendency to believe that only
equipment that gives the most precise recording available can do. Often
people don't even understand what if anything it gives, or attribute
properties to it that are not unique. That equipment was not available
when almost all the landmark studies were done, in some cases was not
available even a few years ago. The equipment available then could not
even do as well as the bottom of what we have. Scientists then had no
problems. When I first worked with the Kay Sonograph, we were feeding it
calls recorded on a fairly inexpensive cassette recorder or reel to
reel. The sonographs were just fine for analysis. Most of the biologists
around here recording frogcalls still do it with cassette. Lots of the
frogloggers have the equivalent of a cheap radio shack cassette, if not
a actual one in them. The same is true of many of the bird scientists
around here, cassette recorders are common. It's hobbyists, not
scientists that have the newer equipment on average. At least as far as
nature recording.
Walt
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