How Do We Hear?
The process of hearing is incredibly complex and first begins with sound waves. Sounds make vibrations in the air around us and are collected on the pinna of the outer ear and funneled to the ear canals.
These waves of sound make the eardrum vibrate. From there, the vibration of the eardrum gets transferred to the Cochlea in the inner ear through the ossicles or ear bones of the middle ear.
The way this happens is the last of the ossicles, the stapes, vibrates and causes the fluid in the cochlea to move in a wave, stimulating the small hair cells.
These hair cells then generate nerve impulses that are converted into meaningful sound in the brain.
How Do We Lose Hearing?
Being able to hear properly requires all parts of the ear to function properly. The type of hearing problem you have is dependent on which part of the auditory system is not working the way it should.
If the problem is in the outer or middle ear, such as a blockage of wax in the ear canal or a perforated eardrum, it’s called conductive hearing loss. This is because the sound vibrations are not being conducted efficiently. Generally this affect the volume of sound so that it doesn’t seem loud enough.
If the issue is somewhere between the cochlea of the inner ear and the brain, it’s called sensorineural hearing loss. This is normally due to damage to the hair cells in the cochlea or the auditory nerve, or because of defects in the pathway leading to the brain.
There are many causes for sensorineural hearing loss, however aging and excessive loud noises are the most common.