The two functions of the inner ear are hearing and balance. The inner ear is made up of specialized parts which help the brain determine motion, body position and sound. The inner ear, outer ear and middle ear work together to provide the sense of hearing.
Located in the skull, the inner ear contains the cochlea, the acoustic nerve and the vestibular system. The cochlea and vestibular system both contain specialized hairs which pick up vibrations. Information about sound or motion is then sent to the brain via the acoustic nerve.
Specifically dedicated to hearing, the cochlea converts sound pressure patterns from the outer ear into electromechanical impulses. The hair cells in the cochlea pick up vibrations and stimulate the cochlea’s nerve cells. These nerve impulses travel along the acoustic nerve to the brain, which then interprets these impulses as sound.
The vestibular system is dedicated to balance. Consisting of the utricle and saccule, the vestibular system also contains hair cells that send information about the position of the head to the brain along a portion of the acoustic nerve. Information from the vestibular system is sent to the brain stem, cerebellum and spinal cord to provide a sense of orientation.