"Kalman Rubinson" wrote in message
...
On Fri, 26 May 2006 23:45:18 GMT, MINe 109
wrote:

[snip]

How about this:
http://illumin.usc.edu/article.php?articleID=45&page=3

If the brain can localize based upon differential delays as small as 10 us,
this implies some discrimination of higher frequencies, not by the mechanism
that senses tone, but by something else. Mathematically, as I am sure you
are aware, this is because there is no such thing as a 20 kHz sine wave that
starts up from nothing. The Fourier series of the startup of a perfect tone
includes higher order coefficients that die away as t -- infinity.

The only mathematical artifacts that are available to discriminate a 10 us
difference are these transient Fourier coefficients. We can't hear the
tones, but somehow, these coefficients get into the brain with the
recognition by neural circuitry that they represent ultrasonics.

BTW, I asked JA to give you a CD of a street recording.