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Pitch perception break-point at 170 Hz
Dear Martin Braun,
After Jont Allen twice objected against your idea of damping basilar
membrane, I am just about explaining the dynamic range as roughly tree
times 40 dB. You are reminding me of a perhaps even more important matter.
Well, I am convinced you are right, and I already tried to provide an
explanation to this phenomenon, puzzling so many researcher. Maybe, my
posting #259 (07/13 this year) was somewhat misleading and partially
incorrect. However, I go on sticking to the following: Neurons preferably
detect coincidence of lowest order. Tonal perception might be based on zero
order ICIs (intra channel coincidence). I got aware that atonal perception
across all CFs starts to become amenable as soon as period exceeds
refractory time. In that case the normally dominating intervals are
presumably getting increasingly corrupted by shorter ones of random length.
The brain may switch to the alternative information bypassing the tonotopy.
This guess of mine seems to backed by a strange sudden change of laterality
after a while, similar to some auditory illusions by Diana Deutsch and
according to experiments by Houtsma.
What about exactly 170 Hz, those who were dealing with related phenomena
are facing uncertainties of psychoacoustic measurement. A figure by Warren
shows the transition for periodic signals with alternating polarity between
100 and 200 Hz. If I remember correctly, Patterson gave a limit for
perception of phase up to 400 or 500 Hz (in good agreement to rarefaction
time). The latter case marks the possibility of what some people call
temporal perception. Values below 200 Hz rather correspond to the change in
You might wonder why I am reluctant to distinguish between temporal
perception below that fairly gradual limit and spectral perception above
it. I just would like to express my heretical opinion that the tonal
perception is based on a temporal mechanism, too.