Objective Measures of Tinnitus in Humans

123 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.Currently, the only means of assessing tinnitus and evaluating tinnitus treatments is by subjective measures (e.g. behavioral tests, questionnaires). Subjective methods, while important for clinical assessment, do not offer a reliable way to distinguish peripherally vs. centrally driven dysfunction in individuals with tinnitus. The goal of this dissertation research was to evaluate objective measures that could be used to diagnose tinnitus and possibly subtype different forms of tinnitus. To determine if group differences existed between individuals with severe tinnitus compared to a non-tinnitus control group, non-invasive objective measures assessing various levels of the auditory system were used. Distortion product otoacoustic emission (DPOAE) input/output functions were calculated to assess cochlear function, contralateral suppression of reflectance-based stimulus frequency otoacoustic emissions was calculated to assess central auditory efferent function, and the auditory middle latency response (AMLR) was measured to assess the central afferent auditory pathway. Results showed significant findings for the reflectance-based SFOAE measure only. The aim of the current study was to use objective measures to group a sample population of individuals with severe tinnitus into categories of tinnitus associated with auditory peripheral dysfunction, auditory central dysfunction, or both peripheral and central dysfunction. Suggested modifications to the current measurements are discussed in order to develop objective protocols for the clinical assessment of tinnitus.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD