->Which membrane? The basilar membrane is responsible for frequency alaysis(AFAIR), but
its limited by its geometry. Doesn't it detect resonances inthe narrowing tube?
Transients could be detected before the pressure wavereaches the basilar membrane, though
I'm just guessing here.<-
Quick review - changes in air pressure cause the eardrum to move. This causes the three
little bones (hammer, anvil, stirrup) to move - these bones are responsible for a great
deal of amplification of sound which is needed when you are trying to vibrate liquid from
vibrating air. The last and smallest bone causes a little membrane on the outside of the
inner ear to vibrate, which sets up vibrations in the fluid of the inner ear. That fluid
causes the basilar membrane to vibrate (the very very short-story version of this is that
the basilar membrane vibrates in different places based on the frequency). Basilar
membrane vibrations, as well as the further amplification gained by active outer-hair-cell
vibration causes potentials to fire in inner-haircells which form synapses with neurons
which eventually send their information, cleaned up a bit, to pathways to the brain.
Transients are still detected by the basilar membrane, but there are stations in the
ascending pathways which deal with transient sounds differently than longer, more periodic
sounds. The moral of the story is that there's still a TON of work to be done just on
pitch perception - and of course even more on general auditory perception.
Matt