occupational noise-induced tinnitus: a review of auditory behavioral and electrophysiological evaluations

Background and aim: the increasing prevalence of noise-induced tinnitus (nit) isconsidered one of the major occupational health threats these days. despite the devastatingeffect of tinnitus on a subject’s performance, auditory functions and life quality, there is alack of standard protocol for its diagnosis and management. furthermore, the mechanismsof nit are not clear yet. so, this review summarized data on nit mechanisms as well asquestionnaires, behavioral and physiologic assessment tools in nit studies.recent findings: based on the authors’ research, 27 eligible articles were included inthis review. nit was mainly bilateral with moderate severity with an overall prevalenceranging from 4% to 73.7%. self-report questionnaires, tinnitus handicap inventory, auditorybrainstem response, otoacoustic emissions and speech in noise tests were the most frequentnit assessment methods in the reviewed studies. our review highlights increased latenciesin brainstem evoked potentials in tinnitus workers, but the knowledge gap about changes atsubcortical and cortical levels remains.conclusion: this review suggests speech in noise test as a useful extension to routine tinnitusassessment by questionnaires among workers. due to insufficient studies and inconsistentresults in nit subjects, more electrophysiological research is suggested in large andhomogeneous samples.