Hearing is one of the most extraordinary senses and is a complex process that involves many parts of the ear to convert sound into viable information. The ear consists of three main parts. The outer ear (the external ear and ear canal), the middle ear (the eardrum and three very small bones that make up the ossicular chain: the malleus, incus, and stapes), and the inner ear (the cochlea and the auditory nerve).
Sound begins with a vibration in the atmosphere known as sound waves. These sound waves first enter the outer ear and are directed down the ear canal where the sound vibrates the eardrum. Next the vibration of sound move to the three little bones. After vibrating the three bones the sound finally travels to the inner most part of the ear called the cochlea. The cochlea consists of tiny hair cells and fluid which help process vibrations into information. The thousands of microscopic hair cells are bent by the wave-like action of the fluid inside the cochlea. The bending of these hairs sets off nerve impulses, which are then passed through the auditory nerve to the hearing center of the brain. This center translates the impulses into sounds the brain can recognized, like words, music or laughter, for instance.
If any one of these delicate systems breaks down, hearing loss can be the result.