Subject: Re: Is there considerable phase locking up to 6 kHz? From: Martin Braun <nombraun(at)TELIA.COM> Date: Wed, 17 Mar 2004 22:44:36 +0100Dear Christian, Dick, Roy, and others, listening to Cheng-Gia's sound file for his example, I also hear that something "goes up". It sounds like a mixture of pitch and timbre change, where neither can be heard clearly. I would suggest, however, that we do not any longer call a timbre change a chance of "place pitch". There is no physiology of a "place pitch", and this concept should be given up. All physiological evidence describes a mechanism of pitch extraction by periodicity detection in the auditory midbrain. There is a physiology of a "place timbre" however. We see two main pathways on which period information can reach the period detectors in the midbrain: a) the proper pitch pathway, which delivers period coding, by phase locking, of resolved harmonics, and b) a secondary pathway, which delivers temporal delay signals that were originally encoded for the purpose of sound localization. Pathway (b) can be activated by many delay signals, such as envelop repetitions or noise repetitions. In Cheng-Gia's example both pitch pathways and the "place timbre" pathway are activated. What the brain does with this muddle depends on its memory and its "good will". Best, Martin -------------------------------- Martin Braun Neuroscience of Music S-671 95 Klässbol Sweden web site: http://w1.570.telia.com/~u57011259/index.htm