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Re: bat recording with AT4022 mic

Subject: Re: bat recording with AT4022 mic
From: "NordicNature" nordicsounds
Date: Fri Jun 3, 2011 2:57 am ((PDT))
Thaks for the links and instruction.
I will try to learn how I should do with these kind of files with bat recor=
dings in post processing.
My remark about it's probably better with a real bat-recorder was aimed not=
 so much about sound quality but more to the frequency range. Without an ul=
trasonic mic/bat detector I'm limited to about 90kHZ. We have bats with up =
to 150kHz here I think.
Of course I'm interested in getting a nice sound quality as well... :)
This was just an experiment because I didn't know how high AT4022 would go =
in frequency... There are sounds that go up to the roof when using 192kHZ s=
etting but I think the sound level might be lower and the noise higher, but=
 I haven't done any real tests. I'm just glad that I'm able to catch some b=
ats in the recordings also when I'm out there recording.

--- In  "Avocet" <> wrote:
> > I have recorded a bat with a standard mic, so it's not as good as
> > you would get with a ultrasound mic or a bat detector of some kind.
> Wanna bet? The mics in affordable bat detectors are no great shakes
> either. They are often Knowles capsules or similar which still have a
> response at bat frequencies but by the time they are HF boosted, they
> get quite hissy. Many electret mics have a useful extended HF
> response.
> > What is the best way to work with the file in post?
> Any suggestions?
> Fork out two zeroes for a specialist bat analysis program or use free
> Audacity which gives you all you want. Parameters are:
>   Call start frequency
>   Call end frequency
>   Repetition rate and pattern - regular or irregular
>   Shape of call - FM (sweep) or CF (constant frequency)
>     or a combination - a "hockey stick" call
> On Audacity you look at:
>   Overall call pattern waveform with timing
>   Normalise the call or part and display the sonogram <spectrum>
>   Select a single call and display the power spectrum
>     <Analyse - Plot Spectrum>
> That's about all that a commercial bat package does. The rest is info
> and a library of bat species calls.
> See Wiki "Bat detector" and Wiki "Bat species identification" I
> expanded the types of bat detector and put some sample displays on the
> second one.
> David
> David Brinicombe
> North Devon, UK
> Cogito cogito ergo cogito sum - Ambrose Bierce

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