Hyperacusis

Hyperacusis is a rare disorder of loudness perception in which sounds that are typically considered harmless become intolerable. The Hyperacusis Network uses the description "decreased sound tolerance." Patients may experience innocuous sounds as painful, frightening, unpleasant, or excessively loud. Hyperacusis frequently co-occurs with tinnitus and can induce considerable distress; patients consistently report impairments in their social, occupational, and recreational activities. Avoiding sound sources and seeking medical attention are common behaviors. Hyperacusis is a distinct diagnosis from phonophobia and misophonia. A fear-based aversion to sound characterizes phonophobia, whereas misophonia involves intense negative emotions, such as anger or disgust, in response to specific trigger sounds, in contrast to the generalized loudness intolerance that defines hyperacusis. Hyperacusis is a symptom that includes an emotional and psychological component, as patients may experience apprehension about sound exposure and engage in avoidance behaviors, in addition to a physiological component involving changes in the central auditory system, such as increased gain. Hyperacusis can have a marked adverse impact on quality of life. Although a definitive cure has not yet been found, research in this area is progressing rapidly, and the number of peer-reviewed studies on the condition has increased 10-fold over the past 40 years.