Talk:Inner ear

It seems that after moving cochlea to a seprate article there's hardly anything to put in 'Inner ear'. What was the motivation behind that? Any information would be appreciated. RockRockOn 22:08, 22 April 2006 (UTC)

overview added

Because I wanted to write about the whale's inner ear, and compare/contrast that with humans, I fleshed out this stub a bit. I added an overview of the ear, leading up to the functions of the inner ear. I don't know how to add things to the log! sorry. Jenzwick 20:14, 13 September 2006 (UTC)jenzwick

non-mammalian information added

In the sentence "The cochlea of the inner ear propagates these mechanical signals as waves in fluid and membranes ..." I'd like to eliminate "as waves" but that's nit-picking (and goes against the standard textbook explanations). As E.R. Lewis pointed out, the wave-length of sound vibrations in inner ear fluids is much larger than the ear itself, so it's not a wave action but more like a sloshing of fluid back and forth between the round window and the oval window.

What makes people assume it's wave action is the waving of the cochlear membrane in response to sound stimuli. That part's true. But tonotopic organization can be achieved without a wavy membrane (as in the amphibian papilla) so the phrase "as waves" isn't essential information, especially for an overview.

Yes, I think you're nit-picking. The "as waves in fluids and membranes" is a fair representation of the "wavy membrane" effect in mammalian cochleas. The long wavelength you're talking about is for compression waves in fluid, which is not at all what's relevant here. Even in the papilla, the "as waves" is correct at some level, since that's really how acoustic energy propagates. I don't think it's a distraction, personally. Dicklyon 00:01, 3 July 2007 (UTC)

The misconception about fluid waves in the cochlea led to various published analyses of impedance matching -- how the middle ear efficiently converts air-borne waves into fluid-borne waves -- and some of that faulty analysis found its way into textbooks. The researchers assumed that there's enough fluid to make waves, and there just isn't that much.

Indeed, the notion of a compression wave led to a lot of bogus stuff. But all the stuff about hydrodynamic waves, long, short, and otherwise, is useful and correct, and can still connect to the idea of middle ear doing a sort of impedance matching (but I don't mean to push that concept, since it gets easily confused). Dicklyon 00:01, 3 July 2007 (UTC

I dont have the Lewis reference handy, but I can find it if anyone wants it. My information is twenty years out-of-date, so perhaps there's a better reference available now. Who knows, maybe they're not publishing that impedance-matching stuff anymore. That's why I'm not making the change yet. When I have time, I'll read the rest of the postings about the cochlea and inner ear to find out whether this is a dead issue.

One of the best current experts on middle ear is Sunil Puria of Stanford. In a 1996 paper in Diversity in Auditory Mechanics, a book I co-edited with Ted Lewis and others, he represents the function of the middle ear as a "two port", which is essentially a model like a fancy transformer or impedance converter, if I may over-simplify. I think it's still a useful concept, but too easy to interpret badly by people who think it's about compression waves. Dicklyon 00:01, 3 July 2007 (UTC)

--ELefty 23:40, 2 July 2007 (UTC)

Of course, this discussion is more relevant to middle ear, and I see that one is very screwed up as you fear. Dicklyon 00:08, 3 July 2007 (UTC)