Subject: Re: AUDITORY Digest - 9 Oct 2005 to 10 Oct 2005 (#2005-208) From: Antje Ihlefeld <ihlefeld(at)BU.EDU> Date: Wed, 12 Oct 2005 07:19:54 -0400In addition to what has been proposed by list members, a useful reference might be a review chapter by Durlach and Colburn 1978. It includes psychophysical data on JND of ITDs of pure-tones and pulsed noise. From looking at my somewhat blurry copy it appears that the JND for noise bursts ranges from 24usec to 4-6usec, depending on the duration of the stimulus. The JND decreases by roughly 2usec for every doubling of duration from 16msec signal duration until about 500msec, at which point it levels off. For pure tones, a plot is included that shows how JNDs depend on frequency. The highest sensitivity of about 12usec is reached around 1kHz, for f>1.5kHz the JNDs become unbounded. (The same book contains another excellent review chapter by Colburn and Durlach about psychophysical models of binaural hearing). I am not sure whether it is really necessary to integrate across frequency in this type of task (integration as in e.g. the straightness and centrality model for localization). Instead, the subject may merely need to detect *some* decorrelation in the stimulus in order to do a discrimination task. A limited set of best frequencies should contain enough information to do this. Antje p.s. The precise reference is: Durlach, NI, and Colburn, HS (1978). “Binaural Phenomena,” Chapter 10 in Handbook of Perception, Vol. 4, Carterette and Friedman (Eds.), Academic Press, NY. AUDITORY automatic digest system wrote: >There are 3 messages totalling 184 lines in this issue. > >Topics of the day: > > 1. Integration of ITD information (3) > >---------------------------------------------------------------------- > >Date: Mon, 10 Oct 2005 19:22:59 +0200 >From: Bernhard Laback <Bernhard.Laback(at)OEAW.AC.AT> >Subject: Integration of ITD information > >Dear list, > >Is there any evidence for integration of interaural time difference >(ITD) information across frequency channels in ITD detection / >discrimination tasks? More specifically, are ITD JNDs lower for a >broadband stimulus compared to any narrowband stimulus within the >spectral range covered by the broadband stimulus? > >Of course, I assume that the overall intensity is held constant. > >I would appreciate any hint, > >With best regards, > >Bernhard Laback > > >