Your Audiology Tutorial: Hyperacusis, Part II

I see it has been almost one year to the day when I composed Part One. Oops. Ah well, let's continue...

Recap: Hyperacusis is described as an abnormal sensitivity to even moderate level sounds, such as that of regular conversational speech. Some patients have specific intolerance to high pitched sounds. Additionally, many patients who have hyperacusis have hearing abilities that are considered to be within normal limits. Some of the conditions and syndromes that may have an association with hyperacusis are Bell's Palsy, Tempromandibular Joint problems (TMJ), Central Nervous System damage, Meniere's Disease, and hypothyroidism.

How to cope? Individuals may alter their environment by:

-wearing earplugs (not advisable unless you are in a very noisy environment)
-disabling buzzers
-disabling telephone ringers
-decreasing the volume of the sound source bothering the individual

Tinnitus, perceptions of noise (ringing, buzzing, pulsing) in the ear, is a condition that often accompanies hyperacusis. It affects about 17% of the world's population, 44 million in the U.S. One source states that 40% of patients with tinnitus also suffer with hyperacusis. Tinnitus will merit its own post at a later date. However, today I will mention the treatments for hyperacusis that are often the same strategies we use for patients with tinnitus.

Tinnitus Retraining Therapy (TRT) is a tool that has been used for some time but was patented by Dr. Pawel Jastreboff, a professor who has served at Emory University in Atlanta. TRT is a treatment that involves intensive directive educational counseling, with frequent follow-up office visits. Often, sound therapy devices are used, recommended to be worn 8 hours daily. The devices are ear-level white noise generators, which emit broadband stimuli.

Listening to white noise at barely audible levels for a prescibed compliance time daily has helped patients with hyperacusis. It is suggested that instead of filtering out sensitive frequencies (by using narrow band stimuli) the patient's ears (and cerebral auditory cortex, perhaps) can be retrained with white noise by promoting a desensitization to all frequencies. Thereby, the patient will eventually become more tolerant to all sounds. Along with the sound therapy, it is advised that the patient gradually increase environmental noise levels and avoid total silence.

However, sometimes narrow band (one frequency) treatment can be successful. In our clinic, a teenage girl reported being so sensitive to everyday sounds she could barely stand to hear her mother speak in a "normal" voice. She stopped attending parties and other social events due to her inability to reconcile even louder sounds. We performed a test which measures Loudness Discomfort Levels (LDLs). The tester plays pure tones that get louder and louder until the patient indicates that the tones are uncomfortably loud. For many people, it takes tones as loud as 90 dB HL and upwards. For this patient, at certain frequencies, she could tolerate no louder than 45 dB HL, which is below everyday speech intensity levels.

During another test which involves the presentation of tones, we noticed that the patient winced when she heard 6000 and 8000 Hz tones. My mentor devised a program in which the patient would listen to a 6000 Hz pure tone on her iPod for prescribed amounts of time. A decreasing tapered dose of listening time would occur over several weeks. Basically, a method to try to desensitize the patient to the offending sound. When the teenager (who was very compliant with the therapy) returned over a month later, she noted that she could now tolerate others' voices. Her LDLs were re-measured: she was able to experience tones of up to 85 and 90 dB HL! A major victory.

Help is available for hyperacusis. Talk to your audiologist, or write me if you need assistance.

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