The electrophysiological markers of hyperacusis: a scoping review

Hyperacusis is known as a reduced tolerance to sounds perceived as normal to the majority of the population. There is currently no agreed definition, diagnostic tool, or objective measure of its occurrence. The purpose of this review is to catalogue the research to date on the use of auditory evoked potentials (AEP) to assess hyperacusis. A step-by-step methodology was conducted following guidelines. Four databases were searched. A total of 3343 papers were identified. A final yield of 35 articles were retained for analysis. The analysis identified four types of aetiologies to describe the hyperacusic population in AEP studies; developmental disorders (<i>n</i> = 19), neurological disorders (<i>n</i> = 3), induced hearing damage (<i>n</i> = 8) and idiopathic aetiology (<i>n</i> = 5). Electrophysiological measures were of short (<i>n</i> = 16), middle (<i>n</i> = 13) and long (<i>n</i> = 19) latencies, believed to reflect the activity of the ascending and descending pathways of the auditory system from periphery to cortex. The results of this review revealed the potential use of electrophysiological measures for further understanding the mechanisms of hyperacusis. However, according to the disparity of concepts to define hyperacusis, definitions and populations need to be clarified before biomarkers specific to hyperacusis can be identified.