Subject: Re: harmonic extraction From: Al Bregman <al.bregman@xxxxxxxx> Date: Wed, 25 Mar 2009 12:46:37 -0400 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Dear James, This example of duplex perception, outside the domain of speech, and clearly not involving two distinct mental "modules", is very interesting, throws a different light on duplex perception of speech, and is certainly worth further development and publication.. Best, Al ------------------------------------------------------------------- Albert S. Bregman, Emeritus Professor Psychology Department, McGill University 1205 Docteur Penfield Avenue Montreal, QC, Canada H3A 1B1. Office: Phone: (514) 398-6103 Fax: (514) 398-4896 Residence phone & fax: (514) 484-2592 www.psych.mcgill.ca/labs/auditory/Home.html ------------------------------------------------------------------- On Wed, Mar 25, 2009 at 10:35 AM, James Bashford <bashford@xxxxxxxx> wrote: > Dear Xueliang Zhang, > > I was intrigued by the interchange between you, Yoshitaka Nakajima, and > Al Bregman, and did some listening, diotically through headphones, to > stimuli consisting of the first 10 harmonics of 100 Hz alternating with the > 5 even harmonics of that stimulus (all harmonics were presented at the same > level). With on/off times for each complex matched at either 0.5 sec or 1.0 > sec (10 ms rise/fall), I hear a fully continous 200-Hz tone that matches the > intensity and timbre of the isolated even-harmonic complex. More > interesting, however, is that the 10-component “all-harmonic” stimulus, > which is heard intermittently, has not only the 100-Hz pitch of that complex > but also retains the loudness and timbre of the all-harmonic stimulus as > heard when it is presented in isolation. Were the even harmonics of the > all-harmonic complex exclusively allocated to support perception of the > continuous 200-Hz complex tone -- leaving only the odd-harmonics to support > perception of the 100 Hz tone -- we would expect both a reduction in > loudness and a clear shift in timbre to the “hollow” quality characteristic > of odd-harmonic signals. This suggests that the “priming” or “capture” > effect observed with complex tones provides an example of duplex perception > that requires neither a verbal stimulus nor dichotic presentation. As I > recall, Al Bregman has previously suggested that such an effect might occur > when nonverbal stimulus input is strongly ambiguous. > > This use of the even-harmonic components to support two simultaneous > percepts (that of both the intermittent “all-harmonic” tone and the > continuous even-harmonic tone) contrasts sharply with the processing > underlying the general phenomenon of illusory continuity that is observed > when one sound alternates with a higher-intensity, potential masking > sound. The latter effect, which has been called auditory induction (Warren, > 1972), occurs with a wide variety of signals, such as tones alternating with > other tones, noise alternating with higher intensity noise, or speech > interrupted by noise (phonemic restoration). This type of continuity, in > which there are no exactly matching components to be found between the > alternating signals, does appear to involve subtractive or exclusive > allocation. For interrupted tones, noise, or speech, continuity is obtained > at the expense of the interrupting signal, which is reduced in loudness by > an amount proportional to the extent the illusion (Warren et al., 1994). > > Warren, R. M., Obusek, C. and Ackroff, J. M. (1972). Auditory induction: > Perceptual synthesis of absent sounds. Science, 176, 1149-1151. > > Warren, R. M., Bashford, J. A., Jr., Healy, E. W., and Brubaker, B. S. > (1994). Auditory induction: Reciprocal changes in alternating sounds. > Perception & Psychophysics, 55, 313-322. > > > > James Bashford > > On Mar 19, 2009, at 5:24 AM, xlzhang wrote: > > Dear list, > A pure tone can extract corresponding harmonic from complex sound when > appearing alternatively. I wonder if a harmonic sound can do the same job? > For example, a complex sound with F0=200Hz appears with a complex sound > with F0=100 Hz, can we get a continuous perception for F0=200Hz? > Thank you for your answers in advance. > > Xueliang Zhang > > --