By Mark Ross
Understanding and P eople with a severe hearing loss
represent only about 10 percent of the
Managing a Severe total population of those with a hear-
ing loss. While this may not seem like
much, it constitutes about three mil-
Hearing Loss lion of the 36 million people in our
country with some degree of hearing
loss. And that is a lot of people.
People with a severe hearing loss
fall into a kind of management limbo.
Those with less than a severe hearing
loss can usually be fitted satisfactorily
with hearing aids. The fitting issues
with them are straightforward: to
select and adjust a specific hearing
aid, one that includes potentially
helpful and desirable special features.
Those with hearing losses in excess
of 90 dB are usually candidates for a
cochlear implant (although some in
this category may still do fairly well
with hearing aids).
It is the people in the middle,
those with a severe hearing loss, who
represent the greatest fitting challenge
as their ability to use residual hearing
varies considerably. In one study, the
range of word recognition scores in
quiet for subjects with severe hearing
loss varied from 10 percent to 100
percent! A similar range was found
while listening in noise. Those with
the poorer scores would likely be
considered potential cochlear implant
candidates, while those who score
above 60 percent should be able to
derive adequate benefit with well-
Hearing assistance is available fitted hearing aids.
for the person with a severe
Severe Hair Cell Damage
hearing loss, either through
When someone has a hearing loss of
well-fitted hearing aids or a about 60-70 dB or more, it is likely
cochlear implant. In order to that the three rows of outer hair cells
realize the most assistance, —known to be particularly susceptible
to all sorts of potentially damaging
it is necessary to ensure
events—are dead or severely damaged.
particularly careful preliminary In such instances, when the outer
testing and, usually, more rows of hair cells are inoperable, it
attention to various amplifica- is only the inner row that “tells” the
brain about the high level of input
tion possibilities than is usually
sounds stimulating the cochlea.
the case. While such a fitting
continued on page 18
may take more time, the
July/August 2010 17
results are worth it.