The Curious case of the Cassowary Call

Subject: The Curious case of the Cassowary Call
From: Chris Corben <>
Date: Mon, 18 Mar 2013 22:55:44 -0500

At such a low frequency, the call will not be in any sense directional, either from the bird's point of view as an emitter or from your microphone's point of view. You are not going to miss the signal from being too close. Most likely, the recording equipment simply cannot respond enough at such low frequencies to give you any perceptible signal, or perhaps the amplifier/speaker you used for playback is not capable of rendering the sound. You should see if you can see the signal in a sonogram. That would give some clues.

Cheers, Chris.

On 03/18/2013 10:18 PM, Arwen B. Ximenes wrote:

Hi again,
something has been bugging me - I'm not sure if I'm barking up the wrong tree 
here, but would distance from the sound source actually be problematic in your 
recording? How close were you, Phil?
>From what I can tell from a quick google, the frequency of the sound you 
describe is approx 36 Hz, which is very low, just within the lower limit of normal 
hearing (of humans) and if the wavelength calculator I have found is correct, then 
at a temp of 25C the wavelength would be 9.6 meters. Does anyone know what the 
minimum distance (nevermind angle) would be from a cassowary to capture its call? 
As I say, I may have got this completely wrong, but you may have been closer, 
which might explain why you didn't pick up the soundwave - can someone set me 
straight on this one?



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