Re: Cochlea Amplifier models : a new list

[Martin Braun <nombraun@xxxxxxxxx>]

Protection does not occur "at the expense of the region tuned to half an 
octave higher". At high sound levels the traveling wave excursions peak and 
then die down half an octave before reaching the OHCs that are tuned to the 
given frequency.

Under physiological conditions vulnerability of OHCs is only a problem if 
sound matches their CF (resonance catastrophe). Under physiological 
conditions off-CF overstimulation of OHCs is not an issue.

In the lab, of course, off-CF overstimulation of OHCs can be so strong that 
damages occur here as well. One result of these experiments is that they 
also show the dissociation of neural tuning and BM tuning, and that the 
passive BM is strategically tuned to take out energy before it reaches the 
OHC that are tuned to this energy.

Martin

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Martin Braun
Neuroscience of Music
S-671 95 Klässbol
Sweden
web site: http://w1.570.telia.com/~u57011259/index.htm




----- Original Message ----- 
From: "Erik Larsen" <elarsen@xxxxxxx>
To: <AUDITORY@xxxxxxxxxxxxxxx>
Sent: Wednesday, October 10, 2007 3:44 PM
Subject: Re: Cochlea Amplifier models : a new list


> What would be the point of protecting the region tuned to the frequency at 
> which high levels of energy are present, at the expense of the region 
> tuned to half an octave higher? As I'm sure you know there is a long list 
> of publications showing this pattern of acoustic injury.
>
> Perhaps the shift in best frequency is an epiphenomenon?
>
> Erik