Objective autonomic signatures of tinnitus and sound sensitivity disorders

Hypersensitivity, phantom percepts, and sensory reactivity are core features of many neurological disorders. Direct, objective measurements of these features have proven difficult to identify, leaving subjective questionnaires as the primary means of assessing sensory disorder severity. Here, we studied neurotypical adults (n = 50) or adults with sound sensitivity and tinnitus (ringing of the ears) (n = 47) and discovered a previously unidentified set of objective measurements that predicted individual differences in the Tinnitus Handicap Inventory (THI) and Hyperacusis Questionnaire (HQ). A neurophysiological assessment of central auditory gain demonstrated an elevation in participants with tinnitus and sound sensitivity but no association with symptom severity. Instead, accurate predictors of individual THI and HQ scores were identified in pupil dilations and facial movements elicited by emotionally evocative sounds. These findings highlight autonomic signatures of disrupted affective sound processing in persons with tinnitus and sound sensitivity disorders and introduce new approaches for their objective measurement.