Re: Is there considerable phase locking up to 6 kHz? (Eckard Blumschein )


Subject: Re: Is there considerable phase locking up to 6 kHz?
From:    Eckard Blumschein  <Eckard.Blumschein(at)E-TECHNIK.UNI-MAGDEBURG.DE>
Date:    Thu, 18 Mar 2004 09:53:10 +0100

Dear all, I appreciate clear objections against the idea of periodicity detection from temporal envelope by Roy Patterson: "The work on IRN stimuli suggests that periodicities are not a necessary and sufficient condition for processing complex pitch, since there are no periodicities in the IRN waveform (see Yost et al, 1996), yet they have a clear pitch (see Yost, 1996a). Our current work suggests that the information for processing the pitch of IRN stimuli is not in the envelope." However, we all should be wary of thoughtlessly using notions like spectrum and temporal fine structure. Already the fundamentally inappropriate traditional spectrogram illustrates that the iteration of a segment of noise without any spectral profile introduces an audible spectral signature. Of course, the FCT-based natural spectrogram shows a more realistic picture of firing pattern in the auditory nerve. I remind those who do not trust in FCT, because they wrongly put it in the drawer of an exotic mathematical idea while it actually replaces FT, of the need to define what we are talking about if we are using terms like spectral component. Martin Braun is certainly correct in that, there are at least two main streams of auditory information within each CN. However, he apparently ignores tonotopy as long as he doesn't follow my suggestion that place code is the best base for subsequent temporal processing. For more than a century, Fourier analysis and place code were considered the basis of hearing and of related audio technology because alternative temporal models failed. Why not seriously dealing with an unseen mathematically correct and physiologically plausible model that unites function of cochlea and brain in a somewhat strange hidden manner which is already known as cepstral analysis? It also may elucidate why different codes contribute to a unitary pitch. I do not appreciate glossing over FCT as a red herring since such emotional arguments are difficult to falsify. Nonetheless, I would hope that expert listeners confirm or deny the putative 400/800 Hz confusion. So far, I am only aware of a plausible 50/100 Hz confusion in case of iterated noise segments with alternating polarity inversion (Warren & Wrightson 1981). Eckard Blumschein


This message came from the mail archive
http://www.auditory.org/postings/2004/
maintained by:
DAn Ellis <dpwe@ee.columbia.edu>
Electrical Engineering Dept., Columbia University