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According to the National Institute on
Deafness and other Communication Disorders, one in three
individuals over the age of 60 and half of those over the age of
85 will have hearing loss. The hearing loss associated with
aging is called presbycusis or high frequency, sensory neural
hearing loss, caused by a deterioration of the VIII nerve. It is
insipid and gradual. For most hearing impaired adults, their
hearing loss began when they were in their late 40’s or early
50’s. It is binaural, permanent and invisible.
Common symptoms of presbycusis are:
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“I don’t have a hearing loss!” Denial is the number one
symptom of age related hearing loss. Hearing loss has very
strong connotations in our youth oriented culture of being OLD,
and old is BAD.
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“I hear just fine, it’s just that everybody mumbles.” In
fact, they are right. Everybody does mumble - because we can. We
spent a lifetime speaking rapidly, slurring our words and
mumbling without it ever interfering with conversation. The
normal ear is such a phenomenal sense organ, it can organize
even the most distorted sounds into a comprehensible signal.
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“What?” This becomes such an automatic response when
something isn’t heard or understood that the hearing impaired
adult won’t even notice that they are using it in every other
sentence in a conversation.
-
“What did he say?” This is a corollary to number 3. It is the
common ‘hearing aide’ for spouses.
The sense of hearing is our most complex
sense organ and probably the most poorly understood by the
average person. The confusion comes from the fact that even
someone with a severe, high frequency, sensory neural hearing
loss can still hear. If an individual couldn’t see, they
would understand they had a problem with their vision.
Logically, if they had a problem with their hearing they assume
it would mean they couldn’t hear, but they can.
Consequently, it is natural for someone to deny they have a
hearing loss even with severe presbycusis.
It is the very nature of our anatomy that causes us to lose high
frequency sensitivity as we age. The VIII nerve is tonotopically
arranged in the cochlea, our sense organ for hearing in the
inner ear. As the nerve spirals around, the high frequencies are
tuned at the basal end and the low frequencies resonate at the
apical end. Sound waves impact the basal end initially and more
forcefully and, like a sheet you shake out over a bed, the
ripples decline in size as you get to the tip. After years of
acoustic bombardment (or excessive noise exposure), the VIII
nerve deteriorates more severely at the basal end of the
cochlea. This results in the high frequency, sensory neural
hearing loss of aging.
This loss of high frequencies has a predictable effect on
communication. In an audiological evaluation, we measure hearing
sensitivity - not acuity. The hearing threshold is the softest
point at which a person hears 50% of the time. We are assessing
only those frequencies which include the sounds of speech, from
250 Hz to 8000 Hz. At the lowest frequencies, sounds such as
vowels, “b”, “d”, “g” are voiced. At the highest frequencies
tested, sounds such as, “p”, “t”, “ch”, “k” occur.
Here is the conundrum of high frequency, sensory neural loss. In
the low frequencies, 90% of the energy of speech occurs, but
these sounds contribute only 10% of the intelligibility. In the
high frequencies, only 10% of the energy of speech occurs, but
these sounds contain 90% of the intelligibility! Removing from
audibility all or most of the high frequency speech sounds
eliminates your ability to understand what is being said, even
though you can still hear “fine.” To the person with presbycusis,
it will sound as if everyone is mumbling.
A distorted signal impacting an intact VIII nerve gets “smoothed
out.” We can fill in the blanks. It’s like gluing together a
broken mug. Even if you are missing the handle, when you’re
done, you can still tell it’s a mug. If you have a distorted
signal matched with a damaged VIII nerve, you aren’t going to
have enough pieces of the mug to glue together, so when it’s
done, you can’t tell if it’s a mug, a bowl, or an ashtray!
There are other serious communication issues caused by
presbycusis. The most debilitating is the diminished ability to
filter speech from background noise. If there are any auditory
distractions in the room, such as other people talking or a
television playing, understanding conversation can be almost
impossible. Another side effect of high frequency VIII nerve
damage is recruitment - an abnormal growth in loudness. If you
intensify the volume of your voice slightly, to the patient with
presbycusis, you will sound like you are shouting. Tinnitus is
also common with this type of hearing loss. Not only will
someone be struggling to hear you above the noise in the room,
they will be fighting against the noises in their head.
One particularly damaging side effect of high frequency sensory
neural loss can be an abnormally poor speech discrimination
ability relative to the hearing loss. A speech discrimination
test is part of a basic audiological evaluation. It measures the
understanding of speech at optimal volume under optimal
conditions. Normally, there is a 1:1 relationship between a
person’s level of hearing loss and their speech discrimination
score. A mild-moderate hearing loss yields a mild loss in speech
discrimination ability. For some individuals, and we don’t
always know why, a mild-moderate hearing loss might yield a
severe speech discrimination deficit. Even under good listening
conditions, this person will have extreme difficulty following a
conversation.
There are many psychosocial issues for the individual with
presbycusis which, when manifested, may be attributed to other
causes depending on the professional lens through which they are
being examined. It is amazing that older friends and relatives
will be given a so-called thorough physical exam and there will
be no evidence of audiogram in the chart. “Mr. Jones, how’s your
hearing?” “Fine, Doc.” End of discussion!
Hearing loss is a major contributor to depression in seniors.
They become so frustrated by
social encounters, going to the movies, talking on the phone,
etc., that they will begin to withdraw and isolate themselves.
They become angry, stressed, and cranky. Older adults with
severe hearing loss are at higher risk for suicide. They suffer
a loss of confidence, especially from the admonishments of their
children, “Are you deaf?” “You only hear what you want to hear.”
They can appear to suffer from dementia because they may be
answering a question that wasn’t even asked. I once asked my
Dad, “How’s business?,” and his response was, “Tickets?! What
tickets?! No one told me I was supposed to pick up tickets!”
There are some simple guidelines that can be observed to ensure
that we are effectively communicating with all of our older
friends and relatives. Similar to Universal Precautions, where
we treat all friends and relatives with the same potential for
communicable diseases, I recommend what I call “Universal
Communication.” There isn’t a single older adult who wouldn’t
benefit from these suggestions, whether they are hearing
impaired or not.
- Speak more slowly, not louder. If you slow your speech down,
you will automatically enunciate more clearly.
- Get closer. When engaging in face to face communication, be
no more than four feet apart. For older adults with whom you
communicate over the telephone, periodically assess their
comprehension of what you are saying. If they are truly
challenged by the telephone, recommend they get a handset
amplifier.
- Get their attention. Calling someone by name is a good way to
focus their attention. If you walk into a room and begin
speaking to someone, you may be halfway through your
conversation before they realize you are even speaking to them.
- Be aware of the environment. Reduce background noise as much
as possible. If it is difficult to eliminate background noise,
do not communicate in the middle of a noisy room. Move to the
side of the room and situate the person with the hearing loss so
their back is to the wall. You have just eliminated 180 degrees
of auditory distractions. If possible, leave a noisy room and go
to quieter surroundings.
- Be on the same level. If you are talking with someone who is
sitting, sit.
- Be conscious of what’s behind you. It is difficult for
someone to pay attention to you if they are fighting the glare
of a sunny day behind your back.
There is no cure for sensory neural hearing loss. Our best
treatment, hearing aides, have their limitations. Unlike glasses
which give us normal vision, hearing aides do not give us normal
hearing. Hearing aides are simply amplifiers. Successful hearing
aide users are highly motivated to make the communication
accommodations necessary for their hearing aides to be
effective.
In conclusion, when planning physical exams for your older
friends and relatives, remember that knowledge of their hearing
status can be of tremendous value to successful rehabilitation.
If you use Universal Communication with all of your older
friends and relatives you will find they will be delighted
because you will be one of the few people they can understand. Sherry Netherland is available for seminars for community and professional groups, Corporate
Wellness Programs, or as a keynote
speaker for your organization. |
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