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9. Re: High frequency recording

Subject: 9. Re: High frequency recording
From: "Raimund" animalsounds
Date: Tue Nov 9, 2010 9:09 am ((PST))
Hi Gus,

such effects might occur at very special circumstances, such as in an elect=
ronic audio system that does not work properly. It requires some kind of no=
nlinear transmission, where one signal modulates another. The technical pri=
nciple behind that is "amplitude modulation" (http://en.wikipedia.org/wiki/=
Amplitude_modulation), which is for instance also being used to produce an =
intermediate frequency in heterodyne radio receivers.

If you removed one of the two inaudible signals from their source, then the=
 resulting difference frequency should also disappear.

Raimund

> Thanks again Raimund - it is my understanding that interactions between i=
naudible high frequencies may cause "beating" or new tones at lower frequen=
cies which are audible - however I also assume the microphone would just re=
cord these reultant audible frequencies regardless of whether or not the in=
audible frequencies were removed.
> However it may have some effect.








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