Hyperacusis

Hyperacusis is a highly debilitating hearing disorder characterized by an increased sensitivity to certain frequencies and volume ranges of sound (a collapsed tolerance to usual environmental sound). A person with severe hyperacusis has difficulty tolerating everyday sounds, which become painful or loud. Hyperacusis is a highly debilitating hearing disorder characterized by an increased sensitivity to certain frequencies and volume ranges of sound (a collapsed tolerance to usual environmental sound). A person with severe hyperacusis has difficulty tolerating everyday sounds, which become painful or loud. Hyperacusis is often coincident with tinnitus. Both conditions have a prevalence of about 10–15% and hearing loss as a major risk factor. However, there also appear to be important differences between the mechanisms involved in tinnitus and hyperacusis. In hyperacusis, the symptoms are ear pain, annoyance, and general intolerance to many sounds that most people are unaffected by. Crying spells or panic attacks may result from the experience of hyperacusis. It may affect either or both ears. Hyperacusis can also be accompanied by tinnitus. Hyperacusis can result in anxiety, stress and phonophobia. Avoidant behaviour is often a response to prevent the effects of hyperacusis and this can include avoiding social situations. Some conditions that are associated with hyperacusis include: The most common cause of hyperacusis is overexposure to excessively high decibel (sound pressure) levels. Some come down with hyperacusis suddenly as a result of taking ear sensitizing drugs, Lyme disease, Ménière's disease, head injury, or surgery. Others are born with sound sensitivity, develop superior canal dehiscence syndrome, have had a history of ear infections, or come from a family that has had hearing problems. Some psychoactive drugs such as LSD, methaqualone, or phencyclidine (angel-dust) can cause hyperacusis. An antibiotic, ciprofloxacin, has also been seen to be a cause, known as ciprofloxacin-related hyperacusis. As one important mechanism, adaptation processes in the auditory brain that influence the dynamic range of neural responses are assumed to be distorted by irregular input from the inner ear. This is mainly caused by hearing loss related damage in the inner ear. The basic diagnostic test is similar to a normal audiogram. The difference is that additionally to the hearing threshold at each test frequency also the lowest uncomfortable sound level is measured. This level is called loudness discomfort level (LDL) or uncomfortable loudness level (ULL). In patients with hyperacusis this level is considerably lower than in normal subjects, and usually across most parts of the auditory spectrum.