Re: About importance of "phase" in sound recognition (David John SMith )


Subject: Re: About importance of "phase" in sound recognition
From:    David John SMith  <smithd@xxxxxxxx>
Date:    Sun, 10 Oct 2010 11:31:02 -0400
List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>

----------MB_8CD36A747E0AAD6_1080_8A1A_web-mmc-d02.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" Many or most of these arguments seem to hinge on semantics.? When we talk= on the phone do we hear the=20 phone transducer or the person speaking on the other end?? Eliminate eithe= r and the connection is lost.=20 Take two sine waves at slightly different frequencies. You hear beats, the= signal amplitude changes as the sin waves "move" in and out of phase.=20 You can say we are hearing phase (differences, changes) or you can say we= are hearing amplitude changes=20 caused by phase.? I'm sure it gets really tricky with more than two freque= ncies - another opportunity for aural illusion? Substituting "onset time" for phase, renders another very interesting but= incomplete specification. We could create waves which do not begin at a zero crossing and (incomplet= ely) describe the resultant clicks in=20 terms of phase, though they would probably be better described in terms of= impulse response. It's particularly interesting to see long mathematical analysis based of= semantic error or incomplete specification! ?=20 Perhaps we can agree that "Phase creates audible effects". cheers, Dave ----------MB_8CD36A747E0AAD6_1080_8A1A_web-mmc-d02.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii" Many or most of these arguments seem to hinge on semantics.&nbsp; When we= talk on the phone do we hear the <br> phone transducer or the person speaking on the other end?&nbsp; Eliminate= either and the connection is lost. <br> <br> Take two sine waves at slightly different frequencies. You hear beats, the= signal amplitude changes as the sin waves<br> "move" in and out of phase. <br> <br> You can say we are hearing phase (differences, changes) or you can say we= are hearing amplitude changes <br> caused by phase.&nbsp; I'm sure it gets really tricky with more than two= frequencies - another opportunity for aural illusion?<br> <br> Substituting "onset time" for phase, renders another very interesting but= incomplete specification.<br> <br> We could create waves which do not begin at a zero crossing and (incomplet= ely) describe the resultant clicks in <br> terms of phase, though they would probably be better described in terms of= impulse response.<br> <br> It's particularly interesting to see long mathematical analysis based of= semantic error or incomplete specification!<br> &nbsp; <br> Perhaps we can agree that "Phase creates audible effects".<br> <br> cheers,<br> Dave ----------MB_8CD36A747E0AAD6_1080_8A1A_web-mmc-d02.sysops.aol.com--


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