Re: back to basics

[Andrew Bell <bellring@xxxxxxxxxxxxxxxx>]

Dear Eckard and list:

I agree that we should look to see if new, improved approaches to refereeing
are possible. Refereeing can be a two-edged sword: at the same time as
cutting out erroneous thinking it can also eliminate new ways of thinking
about old problems.

I can offer one suggestion for improvement. One problem I see is the present
inequality of referee and author. The referee typically remains anonymous,
whereas the author is fully identified. A better, more balanced arrangement
could be one in which both parties remain anonymous to each other -- the
author's name and address, and acknowledgement lines, are blanked out by the
editor before sending out a paper for review. This would allow the paper's
merits to be more objectively assessed. I know a small number of science
journals already do this, and it is a practice that I suggest would improve
the breadth of content of auditory journals as well.

As for your comments about the traveling wave, you are right in emphasising
the importance of phase, which allows us to follow the chain from cause to
effect. In the absence of the proposed Cochlear Mechanics list (proposed
recently by Jont Allen), I would like to go into a few details here
[...content alert: those not interested should pass to the next message
now...]

I agree that Fig. 11 of Rhode and Recio (2000) [JASA 107, 3317] is important
in demonstrating that there are two sources of vibration in the cochlea,
displaced physically (and temporally) by some 3 or 4 cycles. I would like to
point out that the theory of the cochlea as a surface acoustic wave
resonator satisfies that demand: one source (dominant at low SPLs) is the
resonating cavity between the three outer hair cells; the second (active at
higher levels) is the vibration of the tectorial membrane against the
vestibular lip. Moreover, both sources create waves (ripples on the TM) that
travel in opposite directions towards the inner hair cell, where (at a
certain intermediate level) they destructively interfere. Both waveforms and
their interference can be seen in the figure, and the several cycle delay is
simply the path-length difference between the OHC-IHC distance and the
vestibular lip-IHC distance.

For an excellent picture of radial oscillation in the cochlea as revealed by
phase data, I would recommend you look at Nilsen & Russell (1999), which
appeared in Nature Neuroscience, 2, 642-648.  It is available from
http://neurosci.nature.com (or I can send anyone who requests it a PDF
file). Look at the phase data in their Figs.3d and 4d, which show basilar
membrane phase across the partition. The figures show that the OHCs and the
IHC are in phase, but that their phases differ by up to 180 degrees from
that of the surrounding, and intervening, spaces. The suggested picture of
the partition as a SAW resonator neatly explains this result, with the phase
of the wave emerging from the SAW cavity changing rapidly as it travels
across the TM to the IHC. Indeed, the idea that the phase of OHC2 is
opposite to that of OHC1/3 is supported too, with the data showing a
distinct dip under OHC2, even though the measurement spot of the laser diode
is reading the response of the BM, which would tend to integrate the
response of the three OHCs some distance above.

In evaluating Nilsen & Russell's results, it is important to note that they
used a diode with a 5um spot, enabling them to resolve the spatial phase
changes. Other workers, using larger reflective beads (10-30um) dropped onto
the BM, could not hope to see such detail, since the OHCs are little more
than 10um apart.

I would value the opportunity to discuss cochlear mechanics in detail
without fear of overloading the Auditory list. Is there any progress in
implementing a Cochlear Mechanics list?

Andrew Bell.



> -----Original Message-----
> From: AUDITORY Research in Auditory Perception
> [mailto:AUDITORY@LISTS.MCGILL.CA]On Behalf Of Eckard Blumschein
> Sent: Thursday, 21 September 2000 6:53
> To: AUDITORY@LISTS.MCGILL.CA
> Subject: back to basics
>
>
> Dear list,
>
> I would like to first humbly suggest a more flexible system of refereeing
> before commenting again on the question of traveling wave.
>
> Did you get aware of a perhaps not peer reviewed downright editorial
> "What's Shakin' in the Ear?" by Adrian Cho in Science 288, 16 June 2000,
> 1954-1955?
>
> Maybe, the most basic and consequently important work is not always a
> funded one. I do not refer to Bill Gates but to objections, e.g.
> by Seebeck
> (1841/43) or Gold (1948) against questionable concepts like spectral
> acoustic energy and its passive travel along basilar membrane. I was told
> that the maverick Tommy Gold was responsible himself for not getting
> recognized. Well, he was too intelligent as to fight against the two
> anonymous guards, because experiments of that sort may be deathly. When I
> grew up behind the communist firewall, the two heavily armed frontier
> guards were commanded by the party, and the party was always right.
> Nowadays, the web even allows to denounce Lighthill as notoriously driving
> too fast.
>
> Do not get me wrong. I highly appreciate the indispensable and excellent
> work of all referees. However, the system seems to be worth improving. So
> far, nobody feels responsible for anything after the referees' decision.
> Nobody might reckon on funding if she or he just tries to understand
> contradicting facts and consequently puts into question what was accepted
> for good. As a result, a huge number of high quality papers has been
> mounting. Possibly wrong basics are tabooed.
>
> Recio, Rich, Narayan, and Ruggero (1998) backed the travelling wave model
> by reporting (in active as well as death cochleae) "large phase lags and
> the long delays which, according to the one-dimensional long wave theory,
> characterize a traveling wave which transports energy along the cochlea".
> However, Rhode and Recio (2000) wrote "Phase after death. Is there a
> problem?" and "there is a latency difference in the response with the
> high-level response occurring ~100 us earlier than the lower-level
> response". Their Fig. 11 seems to confirm Dancer's idea of gradual
> OHC-resonance build-up. According to Manley, the bird emu contrasts from
> other birds by its mammal-like asymmetrical tuning curves. No matter
> whether or not in this case, hair cell resonance occurs without
> movement of
> the supporting structure, the hydrodynamic model is certainly not
> applicable. The same is true for DPOAE from the gecko. There must be at
> least one other explanation. Mammals, are distinguished by a highly
> developed mechanics performing a predominantly radial motion, being far
> beyond the scope of nowadays hydrodynamic modeling but nonetheless
> understandable. I do not doubt that the critical bandwidth is linked with
> two frequencies of resonance approximately 22% apart from each other on
> condition period does not much exceed 2 ms. Possibly this limit
> is due to a
> geometric constraint of the genetic "design", maybe limited mass of
> Hensen's cells.
>
> Even those who, like me, are not a "nuclear physicist", might be wary. I
> agree with Greenberg that latency of the neural responses has been largely
> underestimated. I am not sure whether place and temporal cues are
> really as
> comprehensive as for instance assumed by McKay, McDermott, and
> Carlyon (2000).
>
> Eckard Blumschein
>