The ear is made up of three parts: the outer ear, the middle ear, and the inner ear. Hearing loss can occur from damage or obstruction to any of these components.

The outer ear is made up of the auricle (or pinna), the auditory canal and the eardrum. The function of the outer ear is to funnel sound from the outside to the hearing system.

The middle ear is an air-filled chamber that houses the smallest bones in the body - the incus, malleus and stapes. The function of the middle ear is to match the impedance of the outer ear to that of the inner ear. The middle ear is attached to the outer ear on one side and to the inner on the other.

The inner ear structure houses the sensory organs for hearing and balance, including the cochlea, vestibules, and semicircular canals. Sound is processed by the fluid-filled cochlea and information regarding balance is handled by the semicircular canals. Motion from the middle ear causes the fluid in the cochlea to move, which triggers small hair cells, located along the entire length of the cochlea, to bend. This action of the hair cells produces a chemical response, which in turn stimulates the corresponding nerve endings to send signals to the area of the brain that processes auditory input.