Klarinet Archive - Posting 000703.txt from 1997/11

From: Bill Hausmann <bhausman@-----.com>
Subj: Re: Nyquist and analog
Date: Thu, 20 Nov 1997 05:42:20 -0500

At 09:11 AM 11/20/97 +0000, Roger Shilcock wrote:
>Can anybody join in????
>On the face of things, human ears don't perform Fourier analysis. Some of
>what has been said seems to suggest that they do, with this stuff about
>hearing or not hearing "components". I thought it was accepted that even
>what would be inaudibly high *components* of an audio signal (meaning, if
>anyone's forgotten, a *musical sound* in the first place) contribute
>additively to what is heard. Even if all the components below 20 KHz can
>be faithfully reproduced, then the original sound is compromised - just as
>it is with analogue recording, for different reasons.
>
As you pointed out in a previous post, "what is sampled is a *resultant*
waveform." But once the higher frequency components have mixed in the air
with the lower ones to create this resultant waveform, you cannot subtract
them out again, nor can you claim they are not present in their original
form and add them in AGAIN. The resultant waveform is the same one analog
recording picks up, and the same one our ears hear, rolled off (if we are
extremely fortunate) around 20 kHz.

Bill Hausmann bhausman@-----.com
451 Old Orchard Drive http://www.concentric.net/~bhausman
Essexville, MI 48732 http://members.wbs.net/homepages/z/o/o/zoot14.html

If you have to mic a saxophone, the rest of the band is too loud.