What is hearing loss?
Hearing loss is a decrease in the ability
to perceive sounds. In adults, hearing loss can be partial or total, sudden or
gradual, temporary or permanent. It can affect one ear or both. The condition
affects approximately 3% of all adult men and women. In general, the risk of
hearing loss increases with age. Between 24% and 40% of adults over age 65 have
difficulty hearing. Thirty percent of people over age 85 are deaf in at least
one ear.
Worldwide, an estimated
500 million people experience hearing loss.
Hearing loss is one of the world's most
common, but most often ignored health problems with far reaching medical,
social and psychological effects. Noise exposure, the ageing process,
ototoxicity (certain medications), infections, head or ear trauma, congenital,
hereditary factors and different types of diseases are some of the factors that
contribute to hearing loss in most people.
What
are the effects of hearing loss?
While hearing loss is one of the world's
most preventable disabilities, it is also one of the most common. The
consequences of hearing loss can be severe and greatly impact the quality of
life and personal relationships of those affected. You may feel isolated and
lonely as hearing loss can have a
profound effect on an individual’s emotional, physical, and social well being.
People with hearing loss are more likely to report symptoms of depression,
dissatisfaction with life, reduced functional health, and withdrawal from
social activities. The good news
is that most people with hearing loss can be helped with hearing aids
thus improving their social and emotional well being.
To
understand hearing loss and treatment, it helps to know how hearing works
Your
ears are extraordinary organs. They pick up the sounds around you and then
translate this information into a form your brain can understand. Your sense of
smell, taste and vision all involve chemical reactions, but your hearing system
is based solely on physical movement. When you understand everything they do,
it's clear that your ears are one of the most incredible parts of your body.
Sounds
are collected at the outer ear and funneled down the canal to the eardrum
(tympanic membrane), which vibrates. The outer part of the ear, known as the
pinna serves to catch the sound waves. This structure helps you determine the
direction of a sound. If a sound is coming from behind you, or above you, it
will bounce off the pinna in a different way than if it is coming from in front
of you, or below you. This sound reflection alters the pattern of the sound
wave. Your brain recognizes distinctive patterns and determines whether the
sound is in front of you, behind you, above you or below you.
The vibrations of the sound waves through the eardrum move the three tiny bones
known as the hammer, anvil and stirrup (malleus, incus & stapes). These in
turn transmit the sounds to the inner ear (cochlea). The cochlea is a small
shell shape structure which is fluid filled. The vibrations from the middle ear
cause waves in the inner ear fluid, stimulating thousands of tiny hair cells.
This movement causes an electrical impulse to travel to the auditory cortex of
the brain. The brain then interprets and decodes the electronic impulses into
recognizable sounds. Any disruption at any stage in this process will result in
a degree of hearing loss.