DEFINITION

• Misophonia refers to an extreme sensitivity to specific sounds produced primarily by human beings, resulting in disproportional reactions of anger, disgust, or distress.
• Possible triggers include eating sounds (slurping, smacking, swallowing, apple eating), nasal or breathing sounds, finger/hand sounds (typing, pen clicking, nail clipping), foot sounds (footsteps, sound of high heels), and repetitive visual movements (leg rocking).
• Often the environmental context affects the severity of the reaction (i.e. the same sound in different situations provokes another response). Sounds produced by family members or acquaintances may elicit more severe reactions.

Episodes follow a typical course:

• Auditory (and sometimes visual) cues are produced by other human beings.
• The sounds provoke an impulsive aversive physical reaction (e.g. muscle constriction, tachycardia), which starts with irritation or disgust that immediately becomes anger.
• The anger, recognized by the patient as excessive, initiates a profound sense of loss of self-control.
• Primary coping strategy is maladaptive behavior such as argumentation or avoidance of the misophonic situation. Alternatively, patients may mimic the trigger or synchronize self-generated sounds to relieve their response.

Misophonia must be distinguished from hyperacusis, wherein the reaction to the aversive sound is directly proportional to sound parameters (frequency and volume) and divorced from the context or meaning associated with the sound.

• Decreased sound tolerance (DST) encompasses both hyperacusis and misophonia.

There is ongoing debate whether misophonia is a psychiatric or auditory disorder, but research suggests it has no relationship with hearing thresholds, and it can develop in the absence of auditory pathology.[1]