Re: About importance of "phase" in sound recognition. ("reinifrosch@xxxxxxxx" )


Subject: Re: About importance of "phase" in sound recognition.
From:    "reinifrosch@xxxxxxxx"  <reinifrosch@xxxxxxxx>
Date:    Sat, 23 Oct 2010 17:16:11 +0000
List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>

------=_Part_1679_8343700.1287854171016 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hello Emad,=20 this is a very late reaction (I have been in Canada), and it is not an answ= er to your question (I am unfamiliar with implants). I hope, however, that = I may have something relevant to say about the influence of phase on timbre= . The finding of Plomp and Steeneken ["Effect of Phase on the Timbre of Com= plex Tones", JASA 46 (1969) 409-421], that the effect is noticeable at low = frequency, may be due to the fact that the strong-vibration zones of the BM= due to sine tones of frequencies f and 2f overlap if f is low. I just did = an experiment on the DX11 music synthesizer with f =3D 55 Hz and 2f =3D 110= Hz. The wave form depends on the delay between the two sine tones, and tha= t delay varies accidentally from one try to the next. Indeed there are slig= ht differences. In some tries the sound is smoother than in other tries. At= 55Hz and 110 Hz, there are inner hair cells the motion of which is a super= position of 55 Hz and 110 Hz, and the moments of time of the nerve potentia= l spikes from these hair cells depends on the wave form. For choir and orch= estra music it is relevant that the just mentioned sound variation is sligh= t.=20 Reinhart. ----Urspr=C3=BCngliche Nachricht---- Von: emad.burke@xxxxxxxx Datum: 13.10.2010 17:09 An: <AUDITORY@xxxxxxxx> Betreff: Re: About importance of "phase" in sound recognition I just had one question about Roy's last email, which is a intriguing quest= ion that i has been puzzling me for quite a long time, and shortly that is = : if the cochlear (mechanics) effects on the perception of sound are that c= rucial as a lot of people in the cochlear modeling community also stress on= , then how would you explain the hearing capabilities of the "deaf-born" pa= tients with the help of cochlear implants that use quite a crude representa= tion of auditory nerve spikes at least compared to super complex structures= that has been developed in the cochlea over the ages. Actually there are v= arious cases that shows after a period of learning, these people can earn a= remarkably significant hearing sense. is there any explanation for this in= your theorem of hearing ? =20 Best Emad ----------------------------------------- Reinhart Frosch, Dr. phil. nat., CH-5200 Brugg. reinifrosch@xxxxxxxx . ------=_Part_1679_8343700.1287854171016 Content-Type: text/html;charset="UTF-8" Content-Transfer-Encoding: quoted-printable <html><head><style type=3D'text/css'> <!-- div.bwmail { background-color:#ffffff; font-family: Trebuchet MS,Arial,Helv= etica; font-size: 12px; margin:0; padding:0;} div.bwmail p { margin:0; padding:0; } div.bwmail table { font-family: Trebuchet MS,Arial,Helvetica; font-size: 12= px; } div.bwmail li { margin:0; padding:0; } --> </style> </head><body><div class=3D'bwmail'><P>Hello Emad, </P> <P>this is a very late reaction (I have been in Canada), and it is not an a= nswer to your question (I am unfamiliar with implants). I hope, however, th= at I may have something relevant to say about the influence of phase on tim= bre. The finding of Plomp and Steeneken ["Effect of Phase on the Timbre of = Complex Tones", JASA 46 (1969) 409-421], that the effect is noticeable at l= ow frequency, may be due to the fact that the strong-vibration zones of the= BM due to sine tones of frequencies f and 2f overlap if f is low. I just d= id an experiment on the DX11 music synthesizer with f =3D 55 Hz and 2f =3D = 110 Hz. The wave form depends on the delay between the two sine tones, and = that delay varies accidentally from one try to the next. Indeed there are s= light differences. In some&nbsp;tries the sound is smoother than in other t= ries. At 55Hz and 110 Hz, there are inner hair cells the motion of which is= a superposition of 55 Hz and 110 Hz, and the moments of time of the nerve = potential spikes from these hair cells depends on the wave form. For choir = and orchestra music it is relevant that the just mentioned sound variation = is slight. <BR>Reinhart.<BR><BR>----Urspr=C3=BCngliche Nachricht----<BR>Von= : emad.burke@xxxxxxxx<BR>Datum: 13.10.2010 17:09<BR>An: &lt;AUDITORY@xxxxxxxx= .MCGILL.CA&gt;<BR>Betreff: Re: About importance of "phase" in sound recogni= tion<BR><BR>I just had one question about Roy's last email, which is a intr= iguing question that i has been puzzling me for quite a long time, and shor= tly that is : if the cochlear (mechanics) effects on the perception of soun= d are that crucial as a lot of people in the cochlear modeling community al= so stress on, then how would you explain the hearing capabilities of the "d= eaf-born" patients with the help of cochlear implants that use quite a crud= e representation of auditory nerve spikes at least compared to super comple= x structures that has been developed in the cochlea over the ages. Actually= there are various cases that shows after a period of learning, these peopl= e can earn a remarkably significant hearing sense. is there any explanation= for this in your theorem of hearing ?&nbsp; <BR><BR>Best<BR>Emad<BR>------= -----------------------------------</P> <P>Reinhart Frosch,<BR>Dr. phil. nat.,<BR>CH-5200 Brugg.<BR>reinifrosch@xxxxxxxx= ewin.ch .<BR><BR></P></div></body></html> ------=_Part_1679_8343700.1287854171016--


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