Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU
Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!ittatc!dcdwest!sdcsvax!ucbvax!spp
From: spp@ucbvax.BERKELEY.EDU (Stephen P Pope)
Newsgroups: net.audio,net.auto
Subject: Re: Phase distortion on music
Message-ID: <12077@ucbvax.BERKELEY.EDU>
Date: Thu, 27-Feb-86 12:39:18 EST
Article-I.D.: ucbvax.12077
Posted: Thu Feb 27 12:39:18 1986
Date-Received: Sat, 1-Mar-86 17:34:33 EST
References: <1582@emory.UUCP> <523@eneevax.UUCP> <445@unccvax.unccvax.UUCP> <1211@mtx5a.UUCP>
Distribution: net
Organization: University of California at Berkeley
Lines: 18
Xref: watmath net.audio:7777 net.auto:9598


I don't remember the reference, but one psychoacoustic study
showed that, for speaker crossovers, the phase distorion was
found to be inaudible (under the condtions of this study)
so long as the frequency response is smooth in the region where
the phase change vs. frequncy was high.  If the frequency
response was uneven, the phase shift was very noticible.

Hence the conclusion, human hearing is insensitive to phase
shift if the frequncy response is flat.  However, this obviously
can't be generalized to the multiple radians of phase shift
found in the passband of a sharp-cutoff LPF, as the CD makers
have found out.

There's also the irrelevant fact that phase carries no information
in speech.

steve