source file: m1460.txt
Date: Sun, 28 Jun 1998 01:44:54 -0700

Subject: Basilar membrane

From: Carl Lumma <clumma@nni.com>

>To see why this is important, you need to know what the critical 
>band is. The basilar membrane is a ribbon-like piece of flabby tissue 
>that flaps around when pressure (sound) waves hit it. Thousands of 
>little hairs mounted on the basilar membrane then vibrate and send 
>messages to the brain, which encode (at least partly) the frequency 
>of the impinging pressure wave. Any given single sine wave excites a 
>small region on the membrane, and the distance in frequency at 
>which two such regions overlap is called the critical band - it varies 
>in frequency and is undoubtedly related to (but not the sole 
>explanation for) the frequency resolving powers of the ear.

Bill Sethares wrote this a long time ago.  His Cd, XENTONALITY, is really
cool, BTW.

My question is: Does anybody know how the basilar membrane works?  I
thought that a given spot on it was sensitive to a particular frequency,
and that these spots were arranged in order of decending frequency along
its length.  Now what stumps me is how a given frequency only vibrates an
isolated part of the membrane.

Carl

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End of TUNING Digest 1460
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