Human Anatomy, Physiology, and Medicine. Anything human!
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After all - I'd think that the brain LACKS the apparatus to sense such sounds, but I don't see any reason why the cochleal hairs would be excited by a particular range of sounds but not by others (especially since the range of sounds one can hear decreases as one ages). As the general trend in biology occurs, the more complex processes/organs/tissues seem to be more specific (perceptual processes), the less complex ones (hairs) tend to be less specific
In response to your question, the organ of corti, the tiny hairlike projections that actually provides a mechanical to bioelectrical impulse that the brain perceives as sound.
These tiny hairs are not broad banded. By that I mean they are somewhat frequency selective. So sound frequencies above or below the resonant frequency has no affect on the hair.
There are hairs in this organ that are tuned to low frequencies, while others are tuned for mid or high, giving us a hearing response range of 16 Hz to 20 KHz, give or take.
We can liken this to a tuning fork, or perhaps a better way to picture this is when a amplified tone generator connected to a amp and speaker with a wine glass next to the speaker, is swept from 0 Hz to say 20 KHz. At some n frequency, the glass will begin to vibrate wildly (Resonance) and shatter.
So if the frequency of sounds is outside the resonance points of the organ of corti, then for all practical purposes, the sound will have no effect.
With that said, I am not sure what will occur to the proceeding organs like the ear drum?
actually, it's the fibers below the organ of corti that make it frequency-selective, not the hairs. The hairs have their important role, but they are all identical.
The hairs in the organ of corti are called hair cells, and are connected to cell receptors. As they vibrate from sound, the move in such a way that opens ion channels that excite neural activity. So the hairs are involved here. Now where I could have been more clear, is the hairs are the same length, but their location in a chamber determines the tuning. Parts of the chamber are shallower than other parts. So the chamber effectivly tunes the hairlike projections.
6 posts • Page 1 of 1
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