Fwd: channel asynchrony ("Eric W. Healy" )

Subject: Fwd: channel asynchrony
From:    "Eric W. Healy"  <ewh(at)SC.EDU>
Date:    Fri, 8 Aug 2003 17:13:07 -0400

Sorry about the "stale" post - it was sent back in March and, due to an apparent glitch on my end, just hit today. -Eric >X-Sender: healye(at)mailbox.gwm.sc.edu >X-Mailer: QUALCOMM Windows Eudora Version >Date: Wed, 12 Mar 2003 16:56:37 -0500 >Reply-To: "Eric W. Healy" <ewh(at)sc.edu> >Sender: AUDITORY Research in Auditory >Perception <AUDITORY(at)LISTS.MCGILL.CA> >From: "Eric W. Healy" <ewh(at)sc.edu> >Subject: channel asynchrony >To: AUDITORY(at)LISTS.MCGILL.CA > >Hi Dave, > >When many frequency bands and a variety of delays are used, larger maximum >delays can be tolerated (Greenberg & Arai, 1998; also see Fu & Galvin, >2001). However, as was pointed out, this does not mean that the delays are >not detectable ("perceptual equivalence"). > >When speech-modulated tones were used in place of speech bands, and when >the number of channels was limited to two (which allows for the strict >isolation of the effect of asynchrony), it was difficult for us to hear >12.5 ms of cross-channel asynchrony. Twenty-five ms was clearly detectable >and produced lowered intelligibility scores. Intelligibility fell toward >zero at 100 ms. This holds for band pairs drawn from various regions of >the speech spectrum (Healy & Bacon, 2000). > >Interestingly, listeners having a hearing impairment have more difficulty >comparing both synchronous and asynchronous across-frequency information, >suggesting that their comparison/integration mechanism may not be as robust >as that of NH listeners (Healy & Bacon, 2002). > >Fu, Q-J, & Galvin, J.J., III. (2001). Recognition of spectrally >asynchronous speech by normal-hearing listeners and Nucleus-22 cochlear >implant users. JASA, 109, 1166-1172. > >Greenberg, S. & Arai, T. (1998). Speech intelligibility is highly tolerant >of cross-channel spectral asynchrony. Joint Meeting of the ASA and the >International Congress on Acoustics, Seattle, 2677-2678. > >Healy, E.W. & Bacon, S.P. (2000). Across-frequency timing in speech >perception: Effective processing of contrasting temporal speech patterns >requires proper synchronous alignment. JASA, 108, 2603(a). > >Healy, E.W. & Bacon, S.P. (2002). Across-frequency comparison of temporal >speech information by listeners with normal and impaired hearing. JSLHR, >45, 1262-1275. > >Hope this helps. > >-Eric >-- >Eric W. Healy, Ph.D. >Assistant Professor >Department of Communication Sciences and Disorders >Norman J. Arnold School of Public Health >University of South Carolina >Columbia, SC 29208 >(803) 777-1087 voice (803) 777-3081 fax > >At 12:00 AM 3/12/2003, you wrote: >>Date: Tue, 11 Mar 2003 12:02:43 +0000 >>From: David Dorran <david.dorran(at)DIT.IE> >>Subject: temporal resolution >> >>Hi, >> >>I've posted this message to the music-dsp list so apologies to anyone who >>recieves it twice (should have posted it here in the first place since its >>more appropriate). >> >>Consider the case where an audio signal is filtered into subbands and each >>subband is passed through a delay (of different duration for each subband) >>before recombination of subbands to produce a new signal. What would be >>the maximum permissible difference between the maximum and minimum delays >>so that the new signal is perceptually equivalent to the original? >> >>Regards, >> >>Dave. >>------------------------------ >> >>Date: Tue, 11 Mar 2003 11:10:27 -0400 >>From: "Dennis P. Phillips, Ph.D." <Dennis.Phillips(at)DAL.CA> >>Subject: Re: temporal resolution >> >>Hi Dave: >> >>Arai & Greenberg (1998) studied speech intelligibility in samples in >>which spectral slices had undergone temporal jitter of this general >>kind. My recollection is that asynchronies up to (and sometimes >>exceeding) 200 ms could support 50%-correct word recognition. >>"Correct word recognition" is, of course, not the same thing as >>"perceptual equivalence". My point is only that the Arai & Greenberg >>article might be a good place to start looking for the evidence you >>need. I hope that this helps. All good wishes, >> >>Dennis >> >>Arai, T., and Greenberg, S. (1998) Speech intelligibility in the >>presence of cross-channel spectral asynchrony. Proc. IEEE Conf. >>Acoust. Speech Signal Proc., Seattle, 933-936. >>----------------------------------- >>Dennis P. Phillips, Ph.D. >>Hearing Research Laboratory >>Professor, >>Department of Psychology >>Dalhousie University >>Halifax, NS, Canada B3H 4J1 >>Phone: (902) 494-2383 >>Fax: (902) 494-6585 >>E-mail: Dennis.Phillips(at)Dal.Ca >>------------------------------ >>Date: Tue, 11 Mar 2003 14:00:32 -0300 >>From: Regis Rossi Alves Faria <regis(at)LSI.USP.BR> >>Subject: Re: temporal resolution >> >>Hello, >> >>auditory system is much more sensitive to modulations of any order than >>the visual system is; >>during my studies with wavelet decomposition/reconstruction of >>audio/musical signals, it became very clear that spectral processing >>done in some >>subbands produces several modulations in the audio signal, which are >>sensed as effects in the sound; >>I wonder what kind of effects different delays applied to subbands would >>cause to the sound, causing the reconstruction to have easily recognized >> >>distortion/modulations even when delays are very short. >> >>regards, >>Regis > >Eric W. Healy, Ph.D. >Assistant Professor >Department of Communication Sciences and Disorders >Arnold School of Public Health >University of South Carolina >Columbia, SC 29208 >(803) 777-1087 voice (803) 777-3081 fax

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DAn Ellis <dpwe@ee.columbia.edu>
Electrical Engineering Dept., Columbia University