Hearing begins when the outer ear, the visible portion of the ear known as the pinna channels sound waves down the ear canal. The ear canal is a tube-like passageway that is lined with tiny hairs and small glands that produce cerumen or ear wax.
The middle ear lies at the end of the auditory canal. It is composed of the eardrum and three small bones, most commonly known as the hammer, the anvil and the stirrup. When sound waves hit the eardrum, it vibrates and, in turn, moves the hammer. The hammer moves the anvil, which moves the stirrup, transmitting the vibrations into the inner ear. The middle ear functions to amplify sound, which is why significant hearing loss can result from any disruption in any of its parts.
The inner ear consists of the cochlea and the nerve of hearing. It converts sound waves into nerve impulses that travel to the brain via the movement of tiny hair cells. The brain, in turn, allows us to hear. Any disruptions or abnormalities along the hearing mechanism can result in decreased or distorted hearing.