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:    Fri, 8 Oct 2010 22:39:16 +0000
List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>

------=_Part_4242_29596891.1286577556004 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hello James, Now I have studied the paper that you recommended, R. Plomp and H.J.M. Steeneken, "Effect of Phase on the Timbre of Complex Tones", J. Acoust. Soc. Am. 46 (1969) 409-421. Some interesting sentences from that paper: Page 413: "The experiment was carried out with nine subjects, all with norm= al hearing. One of them could not observe any difference between the stimul= i, so his results were left out of consideration." Page 420 (Conclusions): "For a fundamental of 292.4 Hz, the maximal effect = of phase on timbre is, averaged over eight subjects, quantitatively equal t= o the effect of changing the SPL by about 2 dB." In the last point of their conclusions, Plomp and Steeneken attribute the e= ffect of phase on timbre to the "[...] correlation [...] between the vibrat= ion patterns at different locations along the basilar membrane and the corr= esponding time patterns of the nerve impulses." Since, according to that paper, the just mentioned effect is comparatively = strong at low frequencies, I redid my synthesizer experiment described earl= ier for a one-octave sine-tone dyad of 110 and 220 Hz. Now I did hear a sli= ght variation of the timbre from one try to the next (in contrast to the 44= 0-880-Hz-case studied before). Reinhart.=20 ----Urspr=C3=BCngliche Nachricht---- Von: jwbeauch@xxxxxxxx Datum: 07.10.2010 19:06 An: <AUDITORY@xxxxxxxx> Betreff: Re: About importance of &amp;quot;phase&amp;quot; in sound recogni= tion [...] To me, the definitive paper on phase discrimination on steady-state c= omplex tones was by Plomp and Sieeneken in 1969: R. Plomp and H. J. M. Sieeneken, "Effect of phase on timbre of complex tone= s", J. Acoust. Soc. Am. 46, No. 2 (pt.2), 409-421 (1969). The prototype signal was a sawtooth but with only 10 harmonics in the Fouri= er series. Phase angles on the harmonics were random multiples of pi/16. The conclusions were: (1) The timbre difference between a tone consisting of only sine or cosine = terms and a tone consisting of alternative sine and cosine terms represents the maximal possible effect of phase on timbre; (2) the maximal effect of phase on timbre is quantitatively smaller than th= e effect of changing the slope of the amplitude pattern by 2 dB/pct and is less for higher than for lower frequencies;=20 (3) the effect of phase on timbre appears to be independent of the effect o= f amplitude pattern and of the loudness factor. [...] Jim Beauchamp Univ. of Illinois ------=_Part_4242_29596891.1286577556004 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'>Hello James,<BR>Now I have studied the p= aper that you recommended,<BR>R. Plomp and H.J.M. Steeneken,<BR>"Effect of = Phase on the Timbre of Complex Tones",<BR>J. Acoust. Soc. Am. 46 (1969) 409= -421.<BR>Some interesting sentences from that paper:<BR>Page 413: "The expe= riment was carried out with nine subjects, all with normal hearing. One of = them could not observe any difference between the stimuli, so his results w= ere left out of consideration."<BR>Page 420 (Conclusions): "For a fundament= al of 292.4 Hz, the maximal effect of phase on timbre is, averaged over eig= ht subjects, quantitatively equal to the effect of changing the SPL by abou= t 2 dB."<BR>In the last point of their conclusions, Plomp and Steeneken att= ribute the effect of phase on timbre to the "[...] correlation [...] betwee= n the vibration patterns at different locations along the basilar membrane = and the corresponding time patterns of the nerve impulses."<BR>Since, accor= ding to that paper, the just mentioned effect is comparatively strong at lo= w frequencies, I redid my synthesizer experiment described earlier for a on= e-octave sine-tone dyad of 110 and 220 Hz. Now I did hear a slight variatio= n of the timbre from one try to the next (in contrast to the 440-880-Hz-cas= e studied before).<BR>Reinhart. <BR><BR>----Urspr=C3=BCngliche Nachricht---= -<BR>Von: jwbeauch@xxxxxxxx<BR>Datum: 07.10.2010 19:06<BR>An:= &lt;AUDITORY@xxxxxxxx&gt;<BR>Betreff: Re: About importance of &amp;= quot;phase&amp;quot; in sound recognition<BR><BR>[...] To me, the definitiv= e paper on phase discrimination on steady-state complex tones was by Plomp = and Sieeneken in 1969:<BR>R. Plomp and H. J. M. Sieeneken, "Effect of phase= on timbre of complex tones", J. Acoust. Soc. Am. 46, No. 2 (pt.2), 409-421= (1969).<BR>The prototype signal was a sawtooth but with only 10 harmonics = in the Fourier series. Phase angles on the harmonics were random multiples<= BR>of pi/16. The conclusions were:<BR>(1) The timbre difference between a t= one consisting of only sine or cosine terms and a tone consisting of altern= ative sine and cosine<BR>terms represents the maximal possible effect of ph= ase on timbre;<BR>(2) the maximal effect of phase on timbre is quantitative= ly smaller than the effect of changing the slope of the amplitude pattern b= y<BR>2 dB/pct and is less for higher than for lower frequencies; <BR>(3) th= e effect of phase on timbre appears to be independent of the effect of ampl= itude pattern and of the loudness factor. [...]<BR>Jim Beauchamp<BR>Univ. o= f Illinois<BR><BR></div></body></html> ------=_Part_4242_29596891.1286577556004--


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