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As printed in Hearing Health, volume 19:4,
Winter 2003
By Marsha Johnson, M.S., CCC-A
Imagine not being able to leave your house because
the sound of the door as it bumps against the jamb hurts
your ears … or giving up your job because you
cannot tolerate the whirring of the fan in your computer.
Imagine that you nearly faint from the squeal of bus
brakes. This is how it is for people who have hyperacusis.
Hyperacusis is a confusing term because it literally
means “better than average hearing,” hardly
an accurate description of a disruptive - even disabling
- condition that may affect several million people in
the U.S. alone. The term refers instead to a change
in a person's auditory system that causes ordinary sounds
or noises to seem unbearably loud. By creating significant
anxiety and apprehension, hyperacusis can also contribute
to a deterioration of general physical health and lead
to negative changes in lifestyle. Associated conditions
frequently include insomnia, depression and loss of
sexual drive.
People who develop severe cases often go to great
lengths to diminish the impact of environmental sounds,
including moving to new homes, purchasing quieter vehicles
or isolating themselves socially. One woman removed
all the electrical appliances from her home, moving
her refrigerator to a nearby garage, in order to escape
having to hear the operation of each device. Although
this may seem an extreme reaction, it is in reality
a rational strategy for a person in her situation.
Most individuals with hyperacusis employ earplugs
and earmuffs to avoid exposure to external noises, a
more practical coping strategy. It has been shown, however,
that utilizing ear protection can worsen the condition,
causing affected people to use more and more, sometimes
several pairs of earplugs at once, further exacerbating
their situation.
Although clinicians have been aware of the condition
for well over 30 years, the medical and audiological
communities were slow to delve into its characteristics
and causes. As recently as 1997, an Internet search
with the keyword hyperacusis resulted in 11 references
to sites containing information. Today, a similar search
produces over 14,000 hits!
For some time, it was most often mentioned as a side
effect of other primary
diseases or serious medical conditions (e.g., aneurysm,
head injury, etc.) but findings are gradually revealing
that hyperacusis could be a primary condition. As a
result, it is now the specific focus of several research
projects.
Hyperacusis has been linked most often with tinnitus,
phantom auditory perceptions that include ringing or
chirping in the ears. In fact, it was the 1985 discovery
by Drs. Pawel Jastreboff, now at Emory University in
Georgia, and Jonathan Hazell, The Tinnitus and Hyperacusis
Centre in London, of a strong correlation between the
two conditions that helped ignite the recent surge in
scientific interest in hyperacusis.
During their research in quest for new treatment protocols
for tinnitus, Jastreboff and Hazell found that about
half of their patients also experienced reduced sound
tolerance. Applying that formula to current estimates
by the American Tinnitus Association that 17 to 43 million
Americans have some degree of tinnitus, we can guess
that 9 to 22 million have some level of hyperacusis.
Although the relationship has yet to be defined, both
clearly are symptoms that reflect auditory system disorder.
It appears that both the peripheral (outer and middle
ear and cochlea) and central (brainstem and central
nervous system) portions of the auditory system are
involved in hyperacusis. Frequently, affected individuals
detect abnormal hearing in only one ear but within a
few days or a week, the vast majority develop bilateral
hyperacusis. Sometimes people notice a more gradual
deterioration of their sound tolerance levels accompanied
by distortion of certain sounds, such as voices or music.
The exact etiology is unknown but there are promising
studies that point to the part of the auditory system
that regulates instructions from the central nervous
system. Every incoming signal is analyzed and responded
to instantaneously by the central nervous system. For
example, the tiny sensations of very soft sounds are
amplified by exaggerated movements of the delicate hair
cells in the cochlea. Very loud sounds are dampened
or inhibited by actions of the middle ear muscles and
bones.
It is theorized in the case of hyperacusis that the
central nervous system does not respond properly to
the incoming signal, miscuing the amplifying or dampening
actions of the cochlea and middle ear. This creates
a situation where an ordinary level of sound, conversational
noise for example, is perceived as if it were as loud
as a jet engine roar.
These problems in central auditory system function
can occur following a head or neck injury, allergic
reactions to pharmaceuticals, ototoxic anti-cancer drugs,
viral or bacterial infections, systemic diseases (e.g.,
autoimmune disorder, Lyme disease, etc.), mastoiditis
or chronic otitis media. Acoustic trauma due to abrupt
pressure changes or excessively loud noises can also
upset the balance between excite/inhibit functions in
the fragile auditory system.
Hyperacusis related to head injuries is particularly
understudied at this time. It can be very challenging
to root out the factors that contribute to this result.
High precision imaging, such as CT scans or MRIs or
PET scans, do not reveal any visible abnormalities in
these cases. In addition, onset of hyperacusis and tinnitus
can be delayed as much as a few weeks post trauma. In
April 2004, our clinic will present new research on
this topic that supports the direct correlation of closed
head injuries and the emergence of these auditory disorders.
In all cases, diagnosis and evaluation of hyperacusis
can be time-consuming and the process is fraught with
challenges directly tied to the secondary psychological
conditions that nearly always accompany it. Among them
is phonophobia, a fear of sound. Severely phonophobic
people may believe that even very soft sounds will permanently
damage their hearing. This causes tension and even panic
in a variety of settings, including a hearing examination.
Another condition, misophonia, has now been identified
and is characterized by hatred of sound. People can
have one or both, adding to the difficulty of making
the important clinical distinction between them. Working
with a coordinated care circle of medical providers,
including psychiatrists, can be appropriate in these
cases.
Once a diagnosis is made, treatment options do exist.
In the mid-1980s, Jastreboff and Hazell themselves developed
a technique, Tinnitus Retraining Therapy (TRT), that
helps many patients to show improved sound tolerance
over time and it has become the primary treatment choice
for hyperacusis.
Patients often benefit from the counseling component
of TRT alone or in combination with a rich auditory
environment. Another facet of TRT entails the application
of broad band sound to stimulate the entire cochlea
in a controllable way via bilateral ear-level devices.
According to a clinical study released by Jastreboff
and Dr. Margaret Jastreboff in 2003, this method often
produces dramatic results in about six months and over
80 percent of treated individuals may achieve complete
recovery from hyperacusis.
Alternatively, pharmaceutical therapies are prescribed,
including anti-depressants, anti-anxiety and anti-obsessive
compulsive medications. Unfortunately, many of these
medications induce undesirable side effects, such as
lethargy and fatigue.
Thousands of people have been diagnosed with hyperacusis,
received appropriate treatment, recovered and returned
to a normal life. This good news needs to reach people
suffering unnecessarily.
Medical professionals – from primary care physicians
to neurotologists, audiologists and psychiatric specialists
– must also be made aware of how to diagnose and
treat hyperacusis. And finally, the insurance industry
must be included so that treatment is eligible for coverage.
With access to information and a supportive team of
professionals, people whose lives are now disrupted
by hyperacusis are able to recover. Everyday sounds
need no longer be something to fear.
Marsha Johnson, M.S., CCC-A, is director
of the Oregon Tinnitus & Hyperacusis Treatment Clinic
in Portland, Ore., a member of the Tinnitus Retraining
Therapy Association and a fellow of the American Academy
of Audiology. She founded the American Hyperacusis Association
in 1999 and has conducted research into autism in children
and hyperacusis associated with head injury. Readers
can contact her at 503.234.1221 or Oregon7@aol.com.
American Hyperacusis Association
www.hyperacusis.org
www.hyperacusis-info.org
Oregon Tinnitus & Hyperacusis Treatment Clinic
www.tinnitustreatment.org
www.tinnitus-audiology.com
The Hyperacusis Network
www.hyperacusis.net
American Tinnitus Association
www.ata.org
800.634.8978
Tinnitus & Hyperacusis Center
www.tinnitus-pjj.com
The Tinnitus and Hyperacusis Centre
www.tinnitus.org |
