Mechanisms of hearing question
F. Frank LeFever
flefever at ix.netcom.com
Sun Dec 13 20:20:32 EST 1998
I'll admit to some ignorance about the fine details of auditory sense
mechanisms, but why do you invoke higher centers in this "tuning"?
Lateral inhibition in the retina works at the retinal level, I believe.
Of course, the retina is ALREADY in the CNS (at the level of the
ganglion cells), so maybe this is not the best comparison, but is it
not possible that lateral inhibition and fine-tuning is at the level of
lateral inhibition between hair cells? Someone out there with a better
grasp of cochlear funcction out there? HELP!
F. Frank LeFever, Ph.D.
New York Neuropsychology Group
In <19981213062632.06806.00002674 at ngol06.aol.com> tonyjeffs at aol.com
>My understanding is that the 'dead' cochlea has a frequency resolution
>around 1/2 an octave, and in vivo it is the 'lateral inhibition'
>the motile outer hair cells (OHCs) that refines this frequency
>Now consider the following:
>IHCs initially detect a sound pressure wave and send the information
>brain. The brain processes this data, and send instructions back to
>appropriate OHCs. The OHCs do their 'fine tuning' work, enabling the
>appropriate IHCs to accurately identify the frequency of the incoming
>If that is approximately correct, I see a problem:-:
>There would be a delay of the order of milliseconds while (1) the
>information is relayed to appropriate brain nuclei, (2) The
>processed, (3) instructions are sent to the OHCs.
>Several milliseconds delay seems rather a long time, particularly as I
>(?) we can hear sounds of a shorter duration than this.
>Is my description along the right lines? I suspect I'm missing
>Could there really such a delay?
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