What is the purpose of the inner ear?

The inner ear can be thought of as two organs: the semicircular canals which serve as the body's balance organ and the cochlea which serves as the body's microphone, converting sound pressure impulses from the outer ear into electrical impulses which are passed on to the brain via the auditory nerve.

When the vibrations of the eardrum have reached the oval window, the sound waves continue their journey inside the inner ear.

The inner ear is a maze of ducts and passages, known as the labyrinth. The vestibule and the cochlea are in the labyrinth.

The cochlea

It is in the cochlea that the sound waves are transformed into electrical impulses that will be transmitted to the brain. The brain translates these impulses into known and understandable sounds.

What is the cochlea and what are its different functions? The cochlea is shaped like a snail. It is filled with a liquid called perilymph and contains two membranes located very close to each other. These membranes form a sort of partition wall in the cochlea. However, for the perilymph to circulate freely in the cochlea on both sides of the partition, the partition is provided with a small orifice (the helicotrème). Thanks to this hole, the vibrations of the oval window are transmitted in any liquid that bathes the cochlea.

When this fluid fluid enters the cochlea, the thousands of microscopic hair fibers lining the cochlea come into motion. There are about 24,000 hair cells, arranged in four long rows.

The auditory nerve

What is the auditory nerve? The auditory nerve is a group of nerve fibers that carry information between the cochlea in the inner ear and the brain. The function of the auditory nerve and transmit the signals from the inner ear to the brain.

The hair cells in the cochlea are all connected to the auditory nerve and are activated according to the nature of the movements in the cochlear fluid.