NERVE HEARING LOSS
The structures involved in
a nerve hearing loss (otherwise called ‘sensorineural’ or ‘perceptive’)
include the cochlea and eighth cranial nerve, are locked away inside the
bones at the bottom of the skull. The sounds of language are coded in
high frequencies and in the low frequencies. When normal hearing people
have difficulty hearing speech sounds in the low frequencies, they
figure them out from what they hear in the high frequencies. In a noisy
background, we count on both.
In addition to affecting the loudness of hearing, nerve hearing loss
produces distortion of the sounds entering the ear. Someone with this
kind of loss may be aware of sounds, but makes errors deciding
exactly what sounds represent. People with a nerve hearing loss
experience difficulty decoding the complicated sounds we string
together to make speech.
In noisy situations, people with a nerve hearing loss - which almost
always affects the high frequencies first - have the greatest
difficulty.
Until recently, most of these losses were attributed to "old age". We
are now wiser and understand that the tendency to develop these losses
probably runs in families and is aggravated by the noise pollution in
our society. In fact, the gene for bringing this hearing
loss may be located on the chromosome very near the gene for longevity,
thus explaining why older people so often have this type of hearing
loss. A preventable cause of such loss is work exposure to loud
noises. Certain medications, occasionally required in the treatment of
life-threatening infections , have been found to damage the hearing
nerve.
The person who has this hearing loss usually doesn't know it.
The damage usually occurs gradually and since we usually don't know what
is going to be said to us, we can only accept what our ears tell us as
the truth. When hearing deteriorates to a moderately severe
level we finally become aware what our ears are telling us can’t
possibly be correct. People who have normal hearing and who
know what they and others are saying know that the person with sensori-neural
loss has lost hearing before they do.
People with a nerve loss have problems communicating with friends and
family. Though they hear what is being said, they often hear it
incorrectly and having a conversation becomes very difficult. Often,
families give up trying to get through to the person who has a nerve
loss. It is a rare friend who continues to try. For the
person with a nerve hearing loss, a public gathering such as a party or
a performance is a disaster. Often the person with a nerve hearing loss
begins to avoid going into public without realizing why. The telephone
becomes a major source of communications, since it is easier to
understand on the telephone than face-to-face at an moderate stage of
deterioration. This explains why so many of our senior citizens spend so
much time on the telephone speaking to people whom they could probably
just as easily visit face-to-face.
Through the next few decades, we don't foresee any readily available
surgical or medical treatment for most nerve hearing losses. The best
ways to improve communications include: