Evaluating of audiotory-vestibular findings in patients with hearing loss due to working in noisy environments: Case- control study

Objective: The aim of this study was to evaluate the hearing system in patients with noise-induced hearing loss (NIHL) by using pure tone audiometry, high frequency audiometry, Distortion Product Otoacoustic Emission (DPOAE) tests and to determine possible damage to the otolithic organs in the vestibular system by using Vestibular Evoked Myojenic Potentials (VEMP) tests. Method: The study included 80 patients from the ages of 25 to 60, and 40 NIHL with 40 control groups. NIHL is a group of people working in noisy environments and hearing loss; the control group consisted of volunteer individuals who did not have any audiovestibular complaints. Pure-tone audiometry, high frequency audiometry, acoustic immitansmetry and distortion product otoacoustic emission tests were performed to evaluate the hearing system in all groups. o-VEMP and c-VEMP tests were used to evaluate the vestibular system. Results: A total of 66 male (82.5%) and 14 female (17.5%) were included in the study. The mean age of the case group was 43.48 ± 1.18 (28-58) and the mean age of the control group was 39.98 ± 1.45 (26-59). A statistically significant difference was found between the case and the control groups at 3,4 and 6 kHz (p <0,01). DPOAE test, according to SNR data, it was found statistically significant at frequencies 2000 Hz and above (p <0,05). According to the results of high frequency audiometry statistical significance is present in all frequencies (p<0,01). When the two groups were compared, there was a significant difference in the threshold intensity and inter-wave amplitude differences in the c-VEMP test (p <0.01); in o-VEMP test, threshold severity, P1 latency, N1 amplitude, P1 amplitude, amplitude difference between the waves were found statistically significant differences (p <0,05). Conclusion: It has been shown that there may be disturbances in both the hearing and balance system of people working in noisy environments. Keywords: Noise-induced hearing loss, high-frequency audiometry, c-VEMP, o-VEMP.