Marc Carter wrote:
In this piece,
<http://www.nih.gov/news/pr/sep2007/nidcd-05.htm>
the author starts off with
"Our ability to hear is made possible by way of a Rube Goldberg-style
process in which sound vibrations entering the ear shake and jostle a
successive chain of structures until, lo and behold, they are converted
into electrical signals that can be interpreted by the brain."
That's a load of bunk. It's not a Rube Goldberg process at all. It's
an incredibly elegant impedance-matching mechanism. It's only "Rube
Goldberg" if you don't understand what the bones do.
m
Later in that same piece, the following is stated--
"When a noise occurs, such as a car honking or a person laughing, sound
vibrations entering the ear first bounce against the eardrum, causing it
to vibrate. This, in turn, causes three bones in the middle ear to
vibrate, amplifying the sound. Vibrations from the middle ear set fluid
in the inner ear, or cochlea, into motion and a traveling wave to form
along a membrane running down its length. Sensory cells (called hair
cells) sitting atop the membrane "ride the wave" and in doing so, bump
up against an overlying membrane. When this happens, bristly structures
protruding from their tops (called stereocilia) deflect, or tilt to one
side. The tilting of the stereocilia cause pore-sized channels to open
up, ions to rush in, and an electrical signal to be generated that
travels to the brain, a process called mechanoelectrical transduction."
Is it true that under ordinary hearing conditions the bending of the
stereocilia is caused by direct contact with the tectorial membrane?
Ken
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Kenneth M. Steele, Ph.D. [EMAIL PROTECTED]
Department of Psychology http://www.psych.appstate.edu
Appalachian State University
Boone, NC 28608
USA
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