Hearing takes place in the brain; the ear is actually the apparatus that provides the brain with the necessary information. There are three parts that make up the ear: the outer ear, middle ear and inner ear.
The outer ear consists of the pinna (the visible part of the ear), the ear canal and the eardrum. Sound waves are captured by the pinna and funneled down the ear canal where they hit the eardrum, causing a vibration.
The middle ear consists of the open space between the eardrum and the oval window, known as the tympanic cavity. Within this space sits the ossicles, a chain of three bones called the malleus, incus and stapes, respectfully. The vibration caused by a sound wave hitting the eardrum is passed through the ossicles until the last bone in the series, the stapes, knocks against the oval window.
The inner ear consists of the oval window, the cochlea, the semicircular canals and the auditory nerve. The semicircular canals are part of the balance system and do not play a role in hearing. The cochlea is a snail-shaped organ filled with fluid and lined with tiny hair cells. When the stapes knocks against the oval window, located on the outside of the cochlea, the movement causes the fluid within the cochlea to move. The movement of the liquid causes the tiny hairs to move, which in turn create an electronic signal. These signals are carried through the auditory nerve to the auditory cortex in the brain. The auditory cortex will then interpret the electrical signals as sound.