Hyperacusis: When Sound Becomes Intolerable

As the father of two deaf sons and the author of a book on the history of cochlear implants, I thought I knew a bit about hearing problems. I was still shocked by an e-mail I received some months ago. Its writer explained that they suffered from extreme oversensitivity to sound. Nothing had helped. In desperation, the writer asked me to suggest an ENT surgeon who would consider surgically deafening them. Doubting that any doctor would agree, I suggested a helmet that cuts out sound completely. I didn’t know whether this existed, but felt sure it must be technically feasible. And for communication with other people, why not learn sign language? I received no response.

This was my first encounter with hyperacusis, though I did not know the term. Analogies with "hyperactive" or "hypertension" are deceptive. Because hyperacusis doesn’t mean super-hearing, some authors prefer other terms. If you have hyperacusis, you’re troubled by sounds that most people wouldn’t find especially loud. Oversensitivity can express itself in various ways, which makes diagnosis difficult. And since many health care practitioners are unfamiliar with it, it may be difficult to get a diagnosis at all.

What is it like?

Someone who suffers from hyperacusis is bothered by everyday sounds. Ordinary sounds, such as traffic or music, are experienced as unpleasantly loud. In some cases, the loudness is accompanied by other sensations, such as pain. Whereas very loud noise is always painful, for sufferers, normal-intensity sounds can be painful. And there are people for whom some common everyday sounds evoke feelings of fear or annoyance. Other researchers accept "fear" but reject "annoyance" as a symptom. Misophonia is generally associated with specific human sounds (such as chewing or breathing).

How common is it?

Though far less well-known, hyperacusis is roughly as common as hearing loss. Approximately 15 percent of American adults (37.5 million) ages 18 years and older report some trouble hearing. One estimate of the prevalence of hyperacusis is from 8 to 15 percent in the general population. Another estimate is a range of 0.2 to 17.2 percent. But there is an interesting difference between the estimates of hearing loss prevalence and hyperacusis prevalence. Hearing loss can be assessed in two ways. One is by asking people if they have problems hearing. The other is through audiometric testing. The first audiometers, for measuring hearing loss, were designed in the 19th century. An early version of the device used clinically today was developed more than 70 years ago. Using these devices, audiologists have developed values for "normal hearing." On this basis, it is estimated that 14.3 percent of Americans 12 years and older have hearing loss in both ears, and 22.7 percent have hearing loss in one or both ears. Not only is hearing loss measurable, there are devices—hearing aids—for correcting it, though many people with hearing loss either don’t have them or don’t use them

For hyperacusis, there are no standards, no equivalent of the audiometer, and approaches to correction are still being developed. The usual way of assessing hyperacusis is by asking people whether they are especially sensitive to everyday sounds. Various questionnaires have been developed. A recent one claims to be a "psychometrically sound and brief tool assessing the severity of hyperacusis in terms of loudness, fear, and pain." As with hearing loss, there are clear variations across demographic groups. Hyperacusis is more common in females and among older people. On the basis of self-reporting, researchers have found it to be relatively common among people who suffer from a wide variety of other conditions, including autism spectrum disorder, migraine, depression, posttraumatic stress disorder, and anxiety. It’s especially common in people suffering from tinnitus, though the causes are believed to be different. But because all the measures are subjective, and the range of symptoms so broad, some clinicians question the value of the numbers.

What causes it?

Hearing loss typically varies with frequency. With hyperacusis, it doesn’t. Sounds are unpleasantly loud regardless of whether the sound falls in the low range (like thunder rumbling), medium range (like human speech), or high range (like a siren or whistle). It’s most likely to be the result of damage to the inner ear. This could have been caused by head injury or by continuous exposure to very loud noise. It has also been suggested that migraine can cause it. But the quick answer is that its cause, or causes, aren’t yet totally clear.

Treatments

Treatment options range from the psychological to the technological to the surgical. In-depth clinical interviews help some patients deal with their reactions to troubling sounds. Patients would be encouraged to talk about how the hyperacusis affects their activities or mood on a typical day. CBT might be recommended if a patient experiences considerable hyperacusis-related distress. Other researchers go for technological solutions. Blocking off all sound would cause communication difficulties (for people who don't know sign language). Researchers at the University of South Florida have developed a multi-function device that fits in the ear and generates therapeutic sound. Finally, a surgical option is being developed. Herbert Silverstein of the Ear Research Foundation has developed a surgical technique that involves reinforcing the bones in the inner ear that regulate sound intensity.

What if I’d known what I know now when responding to that email? I’d have said that surgery has been tried, though it’s certainly not the surgery the writer had in mind. A noise suppression device? Counseling or CBT? I’ve been struck by the contrast with hearing loss, with its audiograms and variety of prosthetic options. But I’m not sure how much more helpful my response would be today than it was then.