Every once in a while, as audiologists we receive a phone call that leaves us mystified. The symptoms related, usually by a parent, don't fit in any of the categories of hearing problems that we have learned to diagnose or treat. A parent may say, "My child can't stand the sound of other children chewing gum" or "My child can't stand the sound of her father's voice." We don't want to dismiss the problem as trivial and yet we don't know where to start. We start thinking of a referral to a psychologist.

A call from the parent of a young woman woke me up. Her daughter could not be in the same room with the family during meal time. She could not tolerate the sound of chewing. The mother did some research and came across the term "misophonia." Bingo! It fit her daughter exactly.

The definition she found in Wikipedia was: "Misphonia, literally 'hatred of sound,' is a form of decreased sound tolerance. It is believed to result from abnormally strong connections between the autonomic and limbic systems in the brain, rather than over-activity in the auditory system itself. The term was coined by American neuroscientists Pawel Jastreboff and Margaret Jastreboff."¹

A similar condition, known as Selective Sound Sensitivity Syndrome, has been documented and is being studied by Marsha Johnson, AuD.²

Its symptoms sound like hyperacusis, but misophonia differs in that the discomfort is limited to certain sounds. Often, as in the case presented by my caller, the intolerance is to the sound of chewing or certain vocal sounds. The problem obviously was affecting her daughter's quality of life, so an appointment was made for a consultation.

Alix is a lovely 22-year-old student who acts perfectly normally-until she is around a person chewing. She then must grit her teeth or leave the room. She also cannot tolerate high-frequency sounds like the squeaking of a pencil or certain electronic sounds. Misophonia was affecting her relationships and her ability to enjoy certain occasions.

Questions abound. Is this a hearing problem or a brain-processing problem? Is the dorsal cochlear nucleus the culprit in that it doesn't inhibit certain sounds? Is the limbic system overreacting and causing a fight or flight reaction?

As we know, the brain is plastic and can become desensitized to certain sounds. That's where audiologists can step in. We have been using retraining therapy for about 15 years for tinnitus. Desensitization should also work for misophonia. Using a pink sound to refocus the auditory cortex's attention from obnoxious sounds may decrease their impact. Over time and with the lessening of the use of earplugs, certain loud sounds may become tolerable.

Alix elected to try wearable sound generators, which emit a soft pink noise. She liked the sound and found it comforting. She tried using behind-the-ear models with open receivers, but she ran into a common problem: misophonia is often accompanied by sensitivity to other stimuli. She could not tolerate the feel of the sound generators. We tried different lengths of receivers as well as different sized domes. They were all annoying. As she was in college and could not make visits for a while, the attempt at retraining therapy was stopped temporarily. She says she is open to trying soft in-the-ear models to see if they will be more comfortable.

This story will need to be continued after she has had a chance to try the new sound generators for a while. In the meantime, the use of music and other pleasant sounds should be in her background on a regular basis as she becomes more comfortable with sound.

The lesson of Alix's story is that audiologists need to take reports of sound intolerance seriously and understand that we may be the only professionals that listen to misophonia patients and provide them with help. This is another case of not saying, "Go home and live with it."

References

1. Misophonia. Accessed online at http://en.wikipedia.org/wiki/Misophonia.

2. Johnson, M. Selective Sound Sensitivity Syndrome. ADVANCE for Audiologists, September 15, 2009. Accessed online at http://audiology.advanceweb.com/Article/Selective-Sound-Sensitivity-Syndrome.aspx.

Dhyan Cassie, AuD, is coordinator of the Tinnitus/Hyperacusis Center at Ear Nose and Throat Professional Associates in Haddonfield, NJ, an adjunct professor at Arizona School of Health Sciences and an advisory board member of the Tinnitus Practitioner's Association, www.tinnituspractitioners.com.