On Mon, 23 Jun 2003 14:49:21 +0000 (UTC), "Didier A. Depireux"
<didier at bluenote.isr.umd.edu> wrote:
>John H. <john at faraway.com> wrote:
>>> The other issue I'd like to raise here is that hearing has two primary
>> processes. Most sound is heard through non-amplification in the inner ear,
>> but there is a mechanism where some hairs are acutely sensitive to v. low
>> levels
>>I am not Tony, but... what are you talking about?
>First, hearing is always amplified. In your ear, you have 1 row of inner
>hair cells, and 3 rows of outer hair cells. The role of the outer hair cells
>is to amplify any incoming sound. Anything below 40 dB or so (it's frequency
>dependent) will be majorly amplified by the OHCs. Objective tinnitus,
>produced inside the cochlea, is due to a group of OHCs spontaneously
>oscillating, thereby causing fluid movement near the inner hair cell and
>causing the sensation of a sound.
>>The ear is a very active system indeed, not a passive frequency
>decomposition system. Unfortunately, it gets so active that it sometimes
>goes awry and generates sounds.
>> Didier
Fascinating! Yours is exactly the kind of expertise I seek to
consult. I am active in a newgroup called rec.pets.dogs.behavior. A
man there is selling a machine that generates some sort of ultrasonic
melody. It costs $130, and he has customers who vow it has been
effective in calming their nervous pets. What do you think? Please
join our discussion there under the heading "Hypersonic Effect: Myth
or Reality?
Thank you in advance.
Charlie
