Download Do you know how we hear

Do you know how we hear?
Hearing begins when the outer ear, the visible portion of the ear that is on the outside of the
head send sound waves down the auditory canal. The middle ear lies at the end of the auditory canal
which is composed of eardrum and three small bones known as the hammer, the anvil and the stirrup.
When the 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
the 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. The brain, in turn, allows us
to hear.
Types of hearing loss :
1.
Conductive :
This could be caused by something as simple as ear wax buildup.
2.
Sensorineural : This is caused when tiny hairs in the cochlea are missing or damaged.
3.
Mixed :
This is combination of conductive and sensorineural hearing loss.
4.
Central :
Hearing Loss due to strokes and central nerve disease.
Causes of hearing loss :
One of the most common “myths” about hearing loss is that only “old people” suffer from it ! In fact the
reverse is true, the majority (65%) of the people with hearing loss are younger than 65 years and about
6 millions are between 18-44 years suffer from hearing loss.
The truth is that there are several causes of hearing loss as follows.
1.
Natural ageing process
2.
Exposure to loud or constant noise
3.
Illness or complications at birth
4.
Heredity/Congenital
5.
Toxic medication
6.
Ear Infections
7.
Trauma/Injury
8.
Tumour