Association Between Noise-Induced Hearing Loss and Vestibular Dysfunction in Workers Chronically Exposed to Occupational Noise

Background: Despite the understanding of the association between noise exposure and noise-induced hearing loss (NIHL), the effects of noise on vestibular function are less well understood and neglected. Aim: The aim of this study was to investigate the function of the vestibular system in workers with NIHL. Materials and Methods: Thirty male textile workers with symmetrical NIHL (49.3 ± 4.5 dB at 4 kHz) and thirty healthy male textile office staff with normal hearing were included in this study. Pure tone audiometry using air conduction and bone conduction was used to determine hearing thresholds. The videonystagmography battery test, including the oculomotor test, caloric test, and video head impulse test (vHIT), was used for the evaluation of vestibular system function. Results: There was no difference in saccadic tracking, smooth pursuit tracking, and optokinetic nystagmus between the two groups. It was found that the abnormal vHIT was significantly higher in workers with NIHL (40%) than in the control group (3.3%). In addition, the abnormal caloric test was significantly higher in workers with NIHL (33.3%) than in the control group (0%). The association between the hearing thresholds of 3, 4, 6, and 8 kHz and vestibular dysfunction was significant. Conclusion: This study provides evidence of the simultaneous occurrence of NIHL and vestibular dysfunction. In other words, the results support the role of noise as a risk factor for the development of vestibular dysfunction in textile workers.