Hyperacusis

Hyperacusis is an increased sensitivity to sound and a low tolerance for environmental noise. Definitions of hyperacusis can vary significantly, but it is often categorized into four subtypes: loudness, pain, annoyance, and fear. It can be a highly debilitating hearing disorder.

There are a variety of causes and risk factors, with the most common being exposure to loud noise. It is often coincident with tinnitus. Proposed mechanisms in the literature involve dysfunction in the brain, inner ear, or middle ear.

Little is known about the prevalence of hyperacusis, in part due to the degree of variation in the term's definition. Reported prevalence estimates in the literature vary widely, and further research is needed to obtain strong epidemiological data. While there are no exact numbers, several people have died by suicide due to the severe consequences of the disease.