Information on
Deafness
Deafness
is the loss of ability to hear normally. There are two types
of deafness conductive and sensori-neural. These may occur separately
or together and one (unilateral) or both ears (bilateral) may
be involved. All degrees of hearing loss, from slight to total,
may occur. Conductive deafness is due to interference with the
conduction of sound across the middle ear to the inner ear.
Sensori-neural deafness is due to reduced function of the inner
ear (cochlea) or the nerve fibres leading to the brain.
How does Deafness occur ?
Deafness caused during pregnancy or at birth is called
congenital deafness. Defects as the foetus develops sometimes
produce congenital conductive deafness. Most cases of deafness
at birth are sensori-neural and are due to German measles
(rubella) affecting the mother in early pregnancy. Rubella
may also cause other defects in the baby apart from deafness.
Less frequently, other infections or complications of pregnancy
and birth may cause deafness. Acquired deafness in children
is most often due to fluid forming in the middle ear. This
condition can be successfully treated and is due to poor function
of the Eustachian tube, a channel which connects the middle
ear to the back of the nose. The commonest cause of deafness
in adults is called presbycusis. It is due to degeneration
of the cochlea (inner ear) as part of the ageing process.
There are many other causes of acquired deafness and these
include wax, injury, infections, rare tumours, some drugs
and Meni re's disease.
Why
does Deafness occur ?
Rubella deafness occurs either because the mother has not
been immunized or has not previously had German measles. If
the mother develops rubella in early pregnancy, there is a
high risk of deafness occurring in the baby. Aging may contribute
to the high frequency tone loss of presbycusis. Very loud
noise in industry or from hobbies, such as pop music or shooting,
may also cause a high tone loss (acoustic trauma). The ears
should be protected by defenders when there is exposure to
very loud noise over prolonged periods. The trauma of head
injury often from accidents can cause both types of deafness.
Treatment
Involved for Deafness
The doctor may want to remove wax from your ears to see if
this benefits hearing. If there is no improvement, a referral
to a specialist may be considered. The specialist will take
a history and carry out an examination. A hearing test and
other tests, including blood examination and x-ray or magnetic
scans may be carried out. It may be necessary to have repeated
hearing tests. Depending on the results and the type of deafness
diagnosed, different treatments may be suggested. For most
patients with sensori-neural deafness the main treatment is
the provision of a hearing aid. Hearing levels are measured
in decibels. If hearing level is say, 30 decibels (30 dB),
then 30% of hearing may have been lost. At this level quiet
conversation will be missed. If the hearing loss is at 30
decibels or greater, then the use of a hearing aid is usually
considered. Modern hearing aids are much lighter and smaller
and better than those of years ago. They can be worn behind
your ear and easily covered by the hair. Even smaller aids
can be purchased to wear in the ear. All hearing aids consist
of a microphone, an amplifier and a receiver. The microphone
picks up the sound, the amplifier makes it louder and the
receiver is a small loudspeaker. Sometimes, making sounds
louder does not help the patient understand better. This is
because the ear has lost the ability to discriminate what
the sounds mean. The latest digital aids may be better for
some patients, but others may do well with a more traditional
type of aid.
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