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From: ron@brl-smoke.ARPA (Ron Natalie <ron>)
Newsgroups: net.audio,net.auto
Subject: Re: Phase distortion on music
Message-ID: <1385@brl-smoke.ARPA>
Date: Fri, 28-Feb-86 00:33:42 EST
Article-I.D.: brl-smok.1385
Posted: Fri Feb 28 00:33:42 1986
Date-Received: Mon, 3-Mar-86 01:15:33 EST
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Xref: watmath net.audio:7801 net.auto:9636

> > 1 (hack, cough, wheeze) speakers.  It wasn't that bad at low volume.
> > However, most car stereo amplifiers have gross phase distortion (pull out
> > your Ford factory radio and run a proof on it) as well as a frequency
> 
> The human ear is insensitive to phase and will not be affected by phase
> distortion, provided the amplitude vs frequency characteristic is not altered.
> The RIAA equalization for records produced horrendous phase shifts
> at some frequencies, but we don't care.  We do speech processing here,
> so we are aware of what one can do to speech, at least.  Some people in
> this department have done 'hi fi' coding, too.  The cheap amplifiers have
> other problems, probably including intermodulation distortion.

Well you telephone people's ear (singular) may be insensitive to phase,
but that makes up part of how we percieve sound direction.  In addition,
if you have two sound sources (like stereo, maybe?) their phase relative
to each other IS essential as making random changes is phase will cause
different perceived sounds when it's summed down into even your single
ear.

-Ron