Describe the process by which vibrations carried by the air are translated into the sensation of hearing by the ear.
The reception of vibration by the ear begins with the passage of vibrations carried in the air down the auditory canal causing the tympanic membrane to vibrate at the same frequency as the waves of air hitting it. The vibrations of the tympanum cause the three tiny bones of the middle ear to move. Their transmission of the vibrations from the tympanum to the oval window enhances the pressure applied to the oval window to over twenty times the pressure of the original air waves. This enhancement allows the ear to detect even faint sounds. The movement of the stapes, the third small bone, causes the oval window membrane to vibrate which, in turn, causes the fluids of the vestibular and tympanic canals to move. As the fluids of the canals move, still at the same frequency of the original air waves, the round window membrane functions as an expansion valve, being pushed outward or being sucked inward as the oval window membrane is pushed in or sucked out, respectively, by the stapes. The movement of the fluid in the vestibular and tympanic canals causes the basilar membrane of the cochlear canal to move up and down in a frequency-dependent manner, which causes the hairs of specific receptor cells to be pushed against the less-motile tectorial membrane. The deformation of the hairs causes the receptor
