wrote:
>
> I know several recent research projects based from Cornell are using
> custom-fabricated Autonomous Recording Units (ARUs), which are small
> weatherized mike/computer combos that record direct to WAV files on hard
> drives. With the current gargantuan capacities of hard discs, they can
> program these things to record several hours a day for weeks at a time,
> unattended. Power comes from a big marine battery.
You can find them in their research pages, but before you run out to buy
one, every page makes it clear they are not for sale. You want one,
design it yourself. Because it's a programmable unit with it's own
microprocessor control it should be nice to use. If they were
inexpensive enough I'd be interested.
Part of how they get such long record times is exotic sampling rates.
The one I saw mentioned was 2 khz, presumably for very low frequencies
only. That seems to be their standard sample rate for their marine
versions, which are primarily being used on whales. They would have to
up the rate quite a bit for birds.
I'm not so sure they are recording to .wav files, I could not find that
confirmed. How variable a sample rate will .wav files handle?
These are a variation on frog loggers used by herp folks for a number of
years. There are commercial frog loggers available if you want to get
into that. The use of this sort of thing is a growing field in many
areas. It's cheaper than deploying a whole bunch of people. I've
considered doing some of it to map frogcall patterns through the night.
That sort of information on frogs is mostly in the heads of a relatively
small group of frogcall experts. We keep comparing notes on when frogs
call, but little formal work of a detailed nature has been done.
One little thing before you jump into this. It does no good to just
record massive amounts of audio, you have to listen to it. This was
learned the hard way in Oceanography, where they discovered the easy
part was collecting all the bottles full of samples. I expect that many
of those departments have now just had to toss a lot of samples. When I
was a student at OSU, we worked out the they were accumulating biologic
samples at a rate of about 3 years analysis work for each year. And that
was being very optimistic about how many people were available for the
analysis. They were something like 10 years behind then, the department
was new.
With some luck it's possible that computers may be able to help some.
But, think about just how crude computer programming is for recognizing
the calls of one species, humans. It has to be trained to the voice of
each individual it's to recognize. So, maybe it will help, but just as
likely it might miss a lot of calls.
I'm somewhat aware of this problem at the moment as I've got a little
monitoring project that's recording a full 160 minutes of mono each
night, and I'm listening to that each day to keep up. A fair chunk of
day tied to earphones.
Walt
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>From Tue Mar 8 18:22:29 2005
Message: 16
Date: Thu, 4 Jul 2002 20:54:41 -0400
From: "Wil Hershberger" <>
Subject: RE: More on MKH and a little story abt. Nagras
I was saying to compare the cassette and the MD. The MD being a digital
format will record the cricket with great fidelity. The cassette will
sound terrible. I can't see why anyone would still use cassette over MD
these days.
Sorry for the confusion
Wil
-----Original Message-----
From: Doug Von Gausig
Sent: Thursday, July 04, 2002 5:39 PM
To:
Subject: RE: [Nature Recordists] More on MKH and a little story abt.
Nagras
At 11:38 AM 7/4/2002, Wil Hershberger wrote:
>If you really want to test the difference between MD and cassette try
>recording a cricket! You will see a MARKED difference in fidelity of
>the two recording media.
How so, Wil? I just took a look at the field cricket from your CD and
compared it to some of my MD recordings of that species. I couldn't see
or
hear anything I'd call a marked difference, but maybe I'm not looking at
the same things. Also I know that your ear is finely-tuned to insect
calls,
and mine is not .
Doug
Doug Von Gausig
Clarkdale, Arizona, USA
Moderator
Nature Recordists e-mail group
http://groups.yahoo.com/group/naturerecordists
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