How is sound propagated from the tympanic membrane to the inner ear?
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Solution
Ear:
The human ear is a balance and hearing organ that detects and processes sound through transduction.
Propagation of sound to inner ear:
Sound waves enter the outer ear and proceed to the eardrum via the ear canal, which is a tiny tunnel..
The incoming sound waves vibrate the eardrum, which transmits the vibrations to three small bones in the middle ear. The malleus, incus, and stapes are the names of these three bones.
The bones in the middle ear amplify, or intensify, sound vibrations before sending them to the cochlea, an inner ear snail-shaped structure filled with fluid. The cochlea is divided into two parts by an elastic partition that runs from the beginning to the end. The basilar membrane is named for the fact that it acts as the foundation, or ground floor, for critical hearing components.
A travelling wave forms along the basilar membrane after the vibrations force the fluid inside the cochlea to ripple. The wave is ridden by hair cells, which are sensory cells located on the basilar membrane. Higher-pitched sounds, like a baby wailing, are detected by hair cells near the wide end of the snail-shaped cochlea. Low-pitched sounds, such as a huge dog barking, are detected by those closer to the centre.
Microscopic hair-like projections (known as stereocilia) that sit on top of the hair cells bump into an overlaying structure and bend when the hair cells move up and down. The stereocilia's tips have pore-like channels that open up when they bend. Chemicals rush into the cells as a result, causing an electrical signal.
This electrical signal is carried by the auditory nerve to the brain, which converts it into a sound that we can identify and interpret.
