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Re: Cochlea Amplifier models : a new list

Erik Larsen wrote:

The data in that figure (nerve response as a function of stimulus level, Fig. 7B) can be taken to suggest any number of things.

This is an unscientific way of talking.

Your interpretation is one possibility, but I could give you several others. For example, as sound level goes up, the fiber's response area broadens, especially towards lower frequencies.

This is not relevant, because rate level peaks are clearly discernible.

This would be entirely consistent with the BM tuning dependence on level, combined with a saturating response of the fiber. The fact that at 100 dB only (not 90 dB) there appear to be two best frequencies could be attributed entirely to the stochastic nature of the fiber response, i.e. at 5.5 kHz the response just happens to be a bit low (only 10% below maximum). There are no error bars so it is not clear whether this is a real dip in the response or not. My interpretation isn't any better or worse than yours if neither of us can offer a stochastic model of the fiber response that explains this data. Its all to easy to find features you are looking for, otherwise.

A "stochastic model of the fiber response" is not needed. The rate count figures are so high that their significance need not be tested by further mathematics.

Another problem is that this data is from the 6 kHz CF place - I assume this is not in the basal turn for squirrel monkey so we really do not know the BM mechanics at that point.

The 6 kHz CF place of the squirrel monkey corresponds to the 3 kHz CF place in humans. Also these things are in the literature!


----- Original Message ----- From: "Erik Larsen" <elarsen@xxxxxxx>
To: <AUDITORY@xxxxxxxxxxxxxxx>
Sent: Thursday, October 11, 2007 5:01 PM
Subject: Re: Cochlea Amplifier models : a new list