Notes On Basilar Membranes

Submitted By bwisott
Words: 403
Pages: 2

Ear canal attached to ear drum
The eardrum attaches to three small bones wich attach to the cochlea.
Cochlea- where sound waves are tranduced to chemical energy. Only 1st 10 harmonics are separated out
Basilar membrane-running along the entirety of the cochlea the basilar membrane feels pressure variations. Specific places of the membrane are tuned to hear specific notes. Characteristic Frequency- this is why different parts of the membrane are suited to hear different variations or vibrations.
Frequency selectivity: the ability of the auditory system to separate out the frequency components of a complex sound.
Thus each place on the basilar membrane acts as an auditory filter, selectively responding to a narrow range of frequencies. The basilar membrane as a whole can be regarded as a bank of auditory filters
Each filter responds to 10% of range
Hair cells have tine hair cells called stereocilia
Outer hair cells- are around 12000 in the human cochlea and are supposed to help fine tuning so that things are sharper and more distinguishable and make us more sensitive to low level sounds
Inner hair cells- around 3500 these cells turn the motion of the basilar membrane to electrical signals. Each hair is also tuned to a pure tone. Thus, the neuron receiving the message from the hair is also tuned
Inner hair cells are the interface between auditory signals and auditory perception
*there are 30000 neurons in auditory nerve. These neurons originate from the apex of the cochlea and respond to loz frequencies. The neurons that stem from the base of the cochlea are tuned to higher