Hyperacusis: Testing, Treatments and a Possible Mechanism

Hyperacusis is a well known phenomenon consisting of a collapse of loudness tolerance. The following generalisations can be made: (1) Hyperacusis is not heightened hearing sensitivity (hearing thresholds are not better than normal); (2) hyperacusis is often accompanied by tinnitus; (3) the severity of hyperacusis is usually inversely proportional to the pitch of the offending noise; (4) perhaps most important, overprotection of the ears is a natural reaction of hyperacusic patients but it must be avoided as it progressively exacerbates hyperacusis. A testing procedure, which involves determining loudness discomfort levels at a number if frequencies, will be described and typical data will be presented. Successful treatment for hyperacusis involves two components: First, training patients to use sound level meters to distinguish between truly damaging sound levels versus those which simply sound too loud; and second, instructing them in the use of a desensitisation program which involves listening to pink noise for several hours daily, starting at a low sound level and progressively increasing it over a period of several months. A new type of protective hearing device will also be described which allows the wearer to avoid loud sounds while preventing over-protection of the ears. When using the device, known as the Star 2001, hyperacusis patients are able to go out and about without fear of encountering loud sounds.The theoretical basis for hyperacusis is not yet known but a potential neural mechanism will be discussed.