Hearing begins when sound waves enter the outer ear (the visible portion of the ear located on the outside of the head) and are channeled down the auditory canal, a tube-like passageway lined with tiny hairs and small glands that produce ear wax.
At the end of the auditory canal lies the middle ear which is composed of the eardrum and three small bones, known by the layman 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. It is the brain that allows you to hear…as long as the message it is receiving is not distorted due to problems in the process just described.
Want to learn more?
What to see the hearing system in action?
View this animated simulation from National Institutes of Health that demonstrates how all the components of the hearing system help our brains hear. Hearing System Simulation.