Re: Wasn't v. Helmholtz right? (Eckard Blumschein )

Subject: Re: Wasn't v. Helmholtz right?
From:    Eckard Blumschein  <Eckard.Blumschein(at)E-TECHNIK.UNI-MAGDEBURG.DE>
Date:    Wed, 31 May 2000 18:11:04 +0200

Dear Andrew Bell,

I very much agree with some important ideas you outlined in your intriguing
paper on the underwater piano.
In particular we share the opinion that the traveling wave is just an
epiphenomenon, but most likely the stereocilia of the outer hair cells act
as the primary sensory elements.

I would merely recommend to not ignore the work of Hudspeth who has shown
that depolarization of the hair cells coincides with opening of ion
channels at surface of the stereocilia. Kiang and more recently Ruggero
gave evidence for immediate response to rarefaction whereas response to
condensation is delayed by half a period. So it would possibly be somewhat
misleading to understand OHCs as reacting to over-pressure.

What about your suggestions of reverberation between adjacent rows of hair
cells, resonant cavities like a laser cavity, etc. I would need much more
precise descriptions in order to be able and follow you. Surface acoustic
waves seems to me more realistic, in principle. However, why did not you
deal with alternative radial oscillations, being already substantiated by
measurements which were published in several abstracts of previous ARO
conferences?

How do you interpret that the tips of the stereocila of the OHCs are
obviously embedded in the tectorial membrane? I refer to N. Slepecky
(1997), "Anatomy of the cochlea and auditory nerve", chapter 107 in
Encyclopedia of Acoustics, p. 1350, Fig. 4.

If neural fibers are able to rapidly convey ions, why not expect the same
inside TM? Because I am qualified an electrical engineer, I tend to makes
such exotic conjectures first.

Do not take me wrong, I would like to stress and acknowledge once again
that you pointed the list to the need for a serious revision of the present
doctrine. Even if the majority might have more problems than me with your
whole paper, I strongly support the publication of what I consider the very
point, i.e. prominent radial resonance. This holds on condition you are
ready to rigorously purify your reasoning from any speculative or
inappropriate stuff, no matter whether or not your models on lattice and
musical ratio could be correct.

Eckard Blumschein