Continued from the previous blog.
Noise-induced hearing loss.
Hearing damage from noise exposure typically occurs in a very
restricted frequency range, creating a gap in the sequence of
frequencies that can be heard. The gap is usually in the
high-frequency range, which can affect a person’s ability to
understand speech. However, noise damage can sometimes affect such a
narrow frequency range that the person may not even be aware that he
has hearing loss.
Protecting your ears from loud sounds
can reduce the potential for hearing loss caused by noise exposure.
Many comfortable forms of hearing protection are available, including
earplugs, which fit into the ear canal, and earmuffs, which secure
over the ears with a band. Some people are reluctant to wear hearing
protection in noisy environments because they are concerned they
won’t be able to hear others talking to them. This is not
something to be concerned about, however, because most people talk
louder in noisy situations, so it is possible to hear conversations
even with ear protection.
I have some noise hearing loss from the
military, but the tests were so poorly done, that I was not able to
contest the results. Over the years, I have become more acutely
aware of some sounds and often have to leave some gatherings when
music is too loud.
Age-related hearing loss. As we
age, hearing loss occurs gradually, beginning with the high
frequencies. In general, vowels, which account for the loudness of
speech, are in the low-frequency range, while consonants, which
provide the clarity of speech, are in the high-frequency range.
Therefore, high-frequency hearing loss may not affect how loudly
sounds are heard, but it can make speech less clear and, as a result,
more difficult to understand. This is especially the case when
watching television or listening to the radio, where speech is often
fast and where visual cues, such as lip movements and body language,
are not as readily available, as well as in noisy situations.
As far as age-related changes in
hearing are concerned, it’s important to remember that the ear
alone is not responsible for hearing. Sound is converted into
electrical signals that travel from the cochlea through a series of
nerve pathways to the brain for interpretation. In addition to
problems associated with physical deterioration of the hair cells in
the cochlea, there are age-related changes in the processing ability
of the hearing-related nerves (the central processing disorders
mentioned earlier) as well as cognitive changes that may slow a
person’s ability to understand speech. These changes can have a
profound effect on a person’s verbal communication abilities,
regardless of whether hearing loss is present. For example, a common
complaint of some older people is that people talk too fast. This is
because as we age, the mental processes that are needed to understand
speech can overload when information is presented too rapidly. In a
study, conducted at the Veterans Affairs National Center for
Rehabilitative Auditory Research (NCRAR) in Portland, Oregon, it was
found that older people who have poorer performance on certain
cognitive tests (those related to thinking, learning, and
remembering) also perform poorly on speech recognition tests (tests
that use lists of sentences speeded up by a computer).
Age-related hearing loss may not be
immediately evident to the person whose hearing is damaged, and as a
result, his hearing may be significantly diminished before he seeks
help. Indeed, older people may not think they have hearing loss at
all. They can still hear a lot of sounds loudly, so they simply
think that other people are mumbling. In fact, this type of hearing
loss is often noticed first by friends and family who find
communication becoming increasingly difficult.
Age-related hearing loss progresses at
different rates in different people. Some people still have very
little loss even in their 80s, although that isn’t common. It is
not clear what makes some people more susceptible to hearing loss
than others, but as with any other age-related condition, good
nutrition, physical activity, and good prevention practices (hearing
protection, in this case) can contribute to lessening the effects or
delaying the onset of hearing loss.
The link between diabetes and hearing
loss has been debated since the 1960s or before, and the results show
that a relationship exists even when researchers account for the
major factors known to affect hearing, such as age, race, ethnicity,
income level, noise exposure, and the use of certain medications.
Diabetes may lead to hearing loss by
damaging the nerves and blood vessels of the inner ear, the
researchers suggest. Autopsy studies of diabetes patients have shown
evidence of such damage.
Diabetes is a group of diseases marked
by high levels of blood glucose resulting from defects in insulin
production, insulin action, or both. Afflicting nearly 21 million
people in the United States, it is a major cause of heart disease and
stroke and the most common cause of blindness, kidney failure, and
lower limb amputations in adults. Prediabetes, which causes no
symptoms, affects about 54 million adults in the United States, many
of whom will develop type 2 diabetes in the next 10 years.
Prediabetes raises the risk of a heart attack or stroke even if
diabetes does not develop. People with prediabetes can often prevent
or delay diabetes if they lose a modest amount of weight by cutting
calories and increasing physical activity.
For other information about diabetes
and deafness or hearing loss please read this, this, and this article.
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