Re: Cochlea Amplifier models : a new list

[Martin Braun <nombraun@xxxxxxxxx>]

> Can you specifically give a reference for studies that show neural tuning 
> at high sound levels which have in some way controlled for response 
> saturation?

Response saturation is not an issue here. You can determine the CFs of a 
neuron at 60 dB and at 90 dB. A half-octave shift of CF, say from 1 kHz to 
1.4 kHz, has to my knowledge never been recorded.

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 5:56 PM
Subject: Re: Cochlea Amplifier models : a new list


There is a dependence of pitch on level, I believe Brian Moore (amongst
others, probably) has published data on this. I think generally the
pitch increases somewhat for high-pitched tones (so that goes in the
right direction, although not by half an octave), and decreases for
low-pitched tones (as we do not have mechanical measurement for apical
regions we don't really know what if any shift occurs there at the level
of the BM). Finally, I believe there is substantial variability in how
large the perceived shift is between listeners, which indicates it
probably depends on more than just peripheral effects, if at all.

In general I would not take psychophysical data as evidence for what
happens in the auditory nerve or on the BM (especially when it comes to
pitch). There are too many intermediate stages and we don't understand
all the transformations, so you have to be a bit careful.

I agree with Dick that saturation in the nerve makes this kind of
comparison between BM and neural tuning more complicated. You would not
be able just to take 'any data' on level dependence of neural responses.
Can you specifically give a reference for studies that show neural
tuning at high sound levels which have in some way controlled for
response saturation?

Thanks,

Erik