Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!decwrl!labrea!aurora!eos!ames!elroy!cit-vax!cit-vlsi!flaig
From: flaig@cit-vlsi.Caltech.Edu (Charles M. Flaig)
Newsgroups: comp.sys.amiga
Subject: Re: Sonic Tomfoolery
Message-ID: <5570@cit-vax.Caltech.Edu>
Date: 26 Feb 88 01:11:44 GMT
References: <319@ardent.UUCP>
Sender: news@cit-vax.Caltech.Edu
Reply-To: flaig@cit-vlsi.UUCP (Charles M. Flaig)
Organization: California Institute of Technology
Lines: 24

In article <319@ardent.UUCP> rap@ardent.UUCP (Rob Peck) writes:
>We have two ears, and two output channels to fool with on the Amiga.

[ lines deleted ]

>But what kind of controls must I apply to make the sound appear
>to be "behind me"?????

As I recall from a class I took last year, the shape of the ear cause
different filtering to take place on sound coming from behind you than
in front of you. 

I believe the simplest effect was that of a low pass filter from behind,
since your ears block high frequencies while low frequencies diffract
around them.  There were also 2nd order effects having to do with the
multiple reflections sound undergoes enroute to your ear canal, which
had a smearing effect (sorry, I forget the details).

______________________________________________________________________________
  ___   ,               ,                                           ,;,;;;,
 /   Y /|              /|              Charles Flaig                ;/@-@\;
|      |/     __, ,__  |/              flaig@csvax.caltech.edu       | ^ |
|      /^\   /  | | |  /  /\  /\                                      \=/ 
 \____/|  \_/|_/\_/ \_/ \_\/_/_/_/     "What, you think they PAY me for this?"