At 07:46 PM 2/5/98 -0500, you wrote:
>If you isolate yourself completely from the surrounding acoustic
>environment (eg in an anechoic chamber that absorbs all sound), you can
>actually hear the Brownian motion of air molecules beating against your
>tympanic membrane (eardrum).
 
William,
 
Have you experienced this personally? My understanding is that the impacts
of individual molecules are far too small to hear. Perhaps what you hear in
a anechoic chamber is the sound of blood moving in the ear, or perhaps an
"after image" of sound created by the brain since we so rarely experience
complete silence.
 
The shell does jumble background noise, which is what makes the ocean sound.
Stand in a noisy room with an appropriately shaped shell to your ear and you
can still hear the "ocean". Someone suggested a couple of years ago when
this topic came up on Conch-L that if you stand in a clothes closet at night
with all sound muffled you cannot hear the "ocean" in the same shell. For
more information see my note "The sound of the ocean" in American
Conchologist 23(1):21 (March 1995).
 
Gary
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Gary Rosenberg, Ph.D.                     [log in to unmask]
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