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From: gvokalek@augean.OZ (George Vokalek)
Newsgroups: comp.dsp
Subject: Re: Psychoacoustics
Summary: Phase sensitivity of ears
Message-ID: <642@augean.OZ>
Date: 8 Nov 89 13:58:01 GMT
References: <1989Oct31.193130.1685@eddie.mit.edu> <19140@pasteur.Berkeley.EDU>
Lines: 22

> What happens when the listener's head turns?  What you really need is a pair of
> headphones that can detect head movements.  Then you must adjust the delays and

The ear is a tube with a transducer at one end.  If the sound pattern is
such that a node is present at the eardrum, no sound will be heard.

By turning the head, you change the pressure distribution in the ear canal,
moving away from the node (possibly toward another node at a different
frequency).

Given the speed of sound is 330m/s, a 3kHz sound will have a wavelength
of about 10cm.  Moving the head by several cm therefore represents a
significant fraction of one wavelength, resulting in a significantly
different sound pattern in the ear.

Note that if this means that you should be able to localise high
frequency sound more accurately than low frequency sound.  Personally,
this seems reasonable - for instance its easy to find a mosquito.
I cant think of any Low freq examples.


..G..