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Hearing Loss is the
Number One Disability in the World
by: Jay Stockman
Hearing loss is prevalent in modern societies as a result of the
combined effects of noise, aging, disease, and heredity. Hearing loss is
the number one disability in the world; approximately 28 million
Americans suffer some type of hearing loss. In addition, 15 of every
1000 people under the age of 18 have a hearing loss, and nearly 90% of
people over age 80 have a hearing impairment. The incidence of hearing
loss is greater in men, than women. The sad part is, that hearing loss
is the most preventable disability in the world.
Hearing is a complicated process involving both the sensitivity of the
ear, as well as the ability to understand, and interpret the speech.
When we hear sounds, we really are interpreting patterns of air
molecules in the form of waves. . The ear is able to pick up these
waves, and convert them into electrical signals that are sent to the
brain. In the brain, these signals are deciphered into meaningful
information, such as language or music with qualities like volume and
pitch. We can characterize sounds in terms of their frequency (or pitch)
and intensity (or loudness).
An individual with hearing in the normal range can hear sounds that have
frequencies between 20 and 20,000 Hertz. Speech includes a combination
of low and high frequency sounds; vowels have lower frequencies and are
easier to hear. Consonants, on the other hand have higher frequencies,
and are harder to hear. Since consonants express most of the meaning of
what we say, someone who cannot hear high frequency sounds will have a
hard time understanding speech.
Intensity, or loudness, is measured in decibels. A normal hearing range
usually ranges from 0 to 140 dB. A whisper is around 30 dB, and normal
conversations are usually 45 to 50 dB. Sounds that are louder than 90 dB
can be uncomfortable to hear. A loud concert might be as loud as 110 dB.
Extreme sounds that are 120 dB or louder can be quite painful and can
result in temporary or permanent hearing loss.
Hearing loss can happen in either frequency or intensity or both. The
severity of hearing loss is assessed on how well a person can hear the
frequencies or intensities most often associated with speech. Severity
of loss can best be described as mild, moderate, severe, or profound.
Deafness is used to describe an individual who has approximately 90 dB
or greater hearing loss. The term "hard of hearing" describes a
condition that is less severe than deafness.
There are many potential causes of hearing loss. These can be divided
into two basic types, called conductive and sensorineural hearing loss.
Conductive hearing loss is the result of the interference of sound
transmission from the outer ear to the inner ear. Common causes include,
inner ear infections, accumulation of fluid in the middle ear, excessive
wax, damage to the eardrum by infection or an injury, or otosclerosis.
This type of hearing loss is temporary, and results in a less severe
form.
Sensorineural hearing loss is due to damage to the pathway from the hair
cells of the inner ear to the auditory nerve and the brain. Common
causes include, age-related hearing loss, injury to the inner ear hair
cells as a result of trauma or noise, abnormal pressure in the inner
ear, stroke, benign lesions, and brain tumors. This type of hearing loss
is more devastating, and is usually more permanent.
The successful treatment of hearing loss depends on the cause. A
bacterial infection of the middle ear can be treated with antibiotics;
blockages of the outer and middle ears can be cleared; damaged eardrums
can be repaired surgically; and ossicles affected by otosclerosis can be
replaced with artificial bones. Some causes of sensorineural hearing
loss can also be improved. For example, an acoustic neuroma can be
removed surgically.
If no cure is successful, a hearing aid for one, or both ears usually
helps, whether the loss is a result of conductive or sensorineural
problems. Many different types of hearing aid are available and an
audiologist will advise as to which type best suits the needs of the
individual.
When a hearing aid does not give adequate amplification, as with
profound deafness, a cochlear implant can help. This device transmits
sound directly into the auditory nerve via electrodes surgically
implanted into the cochlea. Although the sounds heard tend to be of a
buzzing or electronic nature, it can be very useful when used in
combination with lip reading.
About The Author
Jay B Stockman is a contributing editor for Digital Hearing Aids Online
Visit
http://hearing-aidsonline.com/ for more information. |
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