The human ear performs two functions: hearing and balance. Ears pick up vibrations and then change it into signals that the brain interprets as sound. The inner ear contains the semicircular canals and the vestibular organs which tells the brain about any changes in the position of the head. The brain then sends messages to the various muscles that keep the head and body steady.
The human ear is has three parts: the outer ear, the middle ear and the inner ear. The outer ear grabs the sound waves and sends them to the eardrum, a membrane that separates the outer ear from the middle ear. These sound waves cause the eardrum to vibrate.
The middle ear is a small cavity behind the eardrum. Within the middle ear are three bones called, the ossicles. These bones are called: the malleus, the incus, and stapes. These bones receive the vibrations from the eardrum and send them to the oval window, membrane-covered openings between the middle ear and the inner ear.
A tube called the Eustachian tube connects the middle ear to the throat. This tube balances the air pressure on the inner side of the eardrum with that on the outer side.
The inner ear has a fluid-filled structure called the cochlea, which resembles a snail in shape. Vibrations move from the middle ear into the cochlea through the oval window. The vibrations are transmitted to the hair cells in the cochlea and then on to the auditory nerve, which sends the vibrations to the brain. The brain translates these signals into sounds.
Edwards, G.I., & Cynthia Pfirrmann (2009). Barron’s E-Z Biology. Hauppauge, NY: Barron’s
Santi, P. A. (2014). Ear. In World Book Advanced. Retrieved from