The Curious case of the Cassowary Call

To: Chris Corben <>
Subject: The Curious case of the Cassowary Call
From: Dave Torr <>
Date: Tue, 19 Mar 2013 15:04:36 +1100
I suspect that is the case - all equipment has a nominated frequency range
(and usually starts to degrade near the limits of the range). Unless the
equipment is specifically designed for frequencies outside of normal human
hearing I would expect this to be an issue

On 19 March 2013 14:55, Chris Corben <> wrote:

> Hi
> 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?
>> Regards,
>> Arwen
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