About HASC

How We Hear

Understanding how your ear works can help you decide how well you benefit from wearing hearing aids.

To understand the various types of hearing loss, you must first know how your hearing system works:


Sound Waves pass through the auditory canal and beat against the eardrum.


This action causes vibrations in the chain of three small bones in the middle ear.


The third bone, called the stapes or stirrup, is the smallest bone in the human body. It fits into an area called the oval window, located between the middle ear and the inner ear.


When the stapes vibrates with the sound waves passing through, fluid in the inner ear carries the vibrations into the canal of a delicate, spiral structure called the cochlea.


Thousands of hair cells in one part of the cochlea are connected to fibers that make up the auditory nerve. Each hair cell has many microscopic hairs at one end. Movements of the fluid, with the aid of an overlying membrane, bend the tiny hairs. Movement of the hairs stimulates the hair cells to generate electrical impulses, which are carried up the auditory nerve to the brain.

How We Hear Video