Association between suppression of otoacoustic emissions and annoyance levels in tinnitus patients with normal hearing

OBJECTIVE: To correlate the annoyance of tinnitus assessed by the Tinnitus Handicap Inventory and on a visual analogue scale with the evoked otoacoustic emission test result in tinnitus patients with normal hearing. STUDY DESIGN: Case-control study. SETTING: Public tertiary hospital. SUBJECTS AND METHODS: The sample was initially based on a population of 80 subjects with tinnitus; 20 of them had normal hearing and normal evoked otoacoustic emission test results and comprised the study group. For the purpose of comparison, a control group was formed, which consisted of 17 subjects with no hearing complaints and normal hearing. The participants were submitted to hearing tests, immittance testing and tests for the evaluation of acoustic reflexes, distortion product otoacoustic emissions, transient evoked otoacoustic emissions (TEOAEs), and suppression of TEOAEs. The tests were performed in a sound-treated booth using a linear contralateral noise of 60 dB. The presence of suppression effects was defined when the response amplitude was 0.5 dB or higher. RESULTS: Abnormal evoked otoacoustic emission suppression test results were observed in 52.9% of tinnitus patients and in 32.4% of control subjects (p = 0.086). Suppression effects of TEOAEs were absent in 38.5% of subjects with minimal or mild discomfort and in 61.9% of subjects with moderate or severe discomfort (p = 0.183). CONCLUSION: It was not possible to associate the annoyance caused by tinnitus with the TEOAE suppression test results, although suppression effects were found to decrease with increasing annoyance.