A Cross-Sectional Study on the Effect of Chronic Noise Exposure on the Vestibular Function of Traffic Policemen and Automobile Drivers.

Abstract

Noise is a preventable occupational hazard for certain professions like automobile drivers and traffic police personnel. The harmful auditory effects of noise are well known. However, little is known about the status of the vestibular function in chronic noise exposure without noise induced hearing loss. Our objective was to assess the vestibular function in chronic noise exposure. : The study was conducted with a sample size of 242 (chronic noise exposure group - 121, group without chronic noise exposure - 121). Noise estimation was carried out across various traffic intersections to assess the noise exposure levels of the exposed group. All participants underwent a detailed vestibular evaluation in the clinical vestibulometry laboratory. There was no difference in nystagmus, saccades, caloric function between the two groups. The latency and amplitude of vestibular evoked myogenic potentials (VEMP) were similar in both the groups. However, dynamic posturography showed a significant difference in the Adaptation test between the two groups (P < 0.05). We also found a statistically significant difference between the static and dynamic subjective visual vertical (SVV) and the dynamic visual acuity (DVA) between the two groups (P < 0.05). We did not find any clinical evidence of vestibular dysfunction in the noise exposed group. However, the statistical significance of SVV and DVA as seen in this study needs to be evaluated further as an early marker for vestibular dysfunction. It remains to be seen whether the statistically significant prolongation is reversible after the noise exposure is withdrawn.