One reason would be examining recordings of animal sounds that extend into the
ultrasonic. A reasonable number of nominal 'audio' microphones perform decently
in the lower ultrasonic.
Bill R.
>
> This post of Greg's brings up an interesting question for a hearing impaired
> person like myself. Even using both my hearing aids, I don't hear anything
> above 9K. Even people who hear well, as I understand it, rarely hear 20K. So,
> the question is, why should a preamp be called on to amplify frequencies
> above 20 K if nobody can hear it? I frequently see references to magnitudes
> above 20K; I'm guessing this is purely techno babble. I realise of course
> that these frequencies are real, but humans can't hear them any more than
> they can see in the infra red.
> I feel sure that there's a perfectly logical, if complex reason for this, and
> perhaps it's not easy to explain simply, but if it is I'd be interested to
> hear it.
> Cheers
> Max
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