Frequently Asked Ear Questions
The external ear that other people see is only the outer part of a complicated structure. The outer ear and ear canal are arbitrarily referred to as the external ear. The eardrum and the space beyond with the hearing bones, connected to the eustachian tube (which leads to the back of the nose), are referred to as the middle ear. A snail shell-like structure that contains fluid and nerve cells is called the cochlea. The cochlea and the nerve that leads to the brain are called the inner ear. There are also balance structures called semi-circular canals in the inner ear.
A sound wave is collected by the external ear and funneled through the ear canal. The sound wave strikes the eardrum. The eardrum vibrates and transmits the vibration through the three hearing bones, (malleus, incus and stapes) which are the smallest bones in the body. The stapes interfaces with the cochlea, which is fluid-filled. As the stapes moves, a fluid wave is set off through the cochlea and nerve cells move, depending on the type of sound force that is transmitted. The nerve cells, called hair cells, move perhaps like seaweed does underwater (as an example). When the hair cells move, the mechanical force is transferred to electrical activity that sets off the signals that are sent to the brain.