Hyperacusis is a disorder in loudness perception. Patients suffering from hyperacusis may appear overly sensitive to a range of sounds, finding many noises unbearable and painfully loud. Hyperacusis is not the same as "recruitment," a disorder that can be a normal consequence of hearing loss and is associated with abnormal perception of sound as the volume increases.
The condition can affect children and adults, but is considered rare, occurring in an estimated one in 50,000 people. It can be caused by a number of factors. The most common is related to damage to the cochlea from exposure to loud noises such as those experienced at certain work environments, rock concerts, gunfire, air bag deployment in cars and fireworks.
The condition often affects people who have sustained a head injury, as well as those with tinnitus, a common condition in which people hear a ringing noise in their ears. Other causes may include acoustic trauma, adverse reactions to medicine or surgeries, chronic ear infections, and autoimmune disorders.
The hallmark symptom of hyperacusis is having a reduced tolerance and increased sensitivity to everyday sounds in your normal environment. People who suffer from the disease often complain of living in a world in which the volume seems to be turned up too high. Because of this, their quality of life is affected, and they may begin to wear earplugs or earmuffs in public situations where they cannot control the noise.
For people with hyperacusis, the everyday, normal sounds that most people hardly notice suddenly become irritating and painful. Often the most disturbing sounds are sudden, high-pitched noises, such as alarms, bus brakes, the clanging of silverware and dishes, children's screams and clapping.
An audiologist will begin by conducting a thorough physical examination and asking the patient about medical history, including questions about the length and severity of symptoms. A hearing test or audiogram will be given, which is a graph that depicts a person's ability to hear sounds at different frequencies.
It is important to note, however, that most people with true hyperacusis don't appear to have any hearing loss as measured and recorded on an audiogram. They may have difficulty hearing speech in noisy environments or in poor listening conditions, even when hearing tests show no hearing loss. This is sometimes called obscure auditory dysfunction or auditory processing difficulty.
Although a corrective surgical or medical approach for treating hyperacusis is not available at this time, there are a number of existing therapies that can help reduce a person's fears and anxieties about the disease, as well as their acutal sensitivity to sounds. These may include retraining and acoustic therapies.
Retraining therapy consists of counseling and acoustic therapy. The aim is to reduce a patient's reactions to hyperacusis. Counseling is designed to help a patient better cope, while acoustic therapy is used to decrease a patient's sensitivity to sounds and to teach them to view sound in a positive manner.
Reviewed by health care specialists at UCSF Medical Center.