How Do We Hear?

The design of our hearing system is complex, elegant and still a challenge for people to evaluate and treat.

After sound waves are collected by the outer ear, they travel down the ear canal and vibrate the ear drum (tympanic membrane). Behind the ear drum is a small chamber which is intended to be filled only with air. Within the middle ear are 3 small bones that create a link between the ear drum and the fluid that fills the inner ear. The inner ear has two chambers: one which houses 100,000 microscopic specialized nerve cells that are arranged in 4 rows and spiral two and half times within the cochlea and one which consists of 3 loops oriented in different directions and called the vestibular system. The entire inner ear chamber is bathed in two different fluids which are separated by the thin membrane.
 

The cochlear nerves are the ones that allow us to translate different sized sound waves (sounds) into an electrical signal that is then quickly passed through a bundle of 7 different neural connections into that part of the brain that allows us to translate those sounds into meaningful noises, words and music.
 

The vestibular nerves are more than one type of specialized design. They detect the presence of gravity and movements of the head. One part of this system relies on a cluster of tiny particles, embedded in a gelatin. When the vestibular nerves are injured, a person experiences dizziness. But remember that dizziness has other sources, such as a problem in the job of the brain to translate the information that it is receiving.