Investigating the prevalence of hearing loss and its related factors in professional drivers in Shahroud city, Iran.

Objectives. A cohort study was designed and implemented to determine the prevalence of hearing problems and their related factors in professional drivers in Shahroud city. Methods. In total, 1461 professional drivers were examined. Demographic information, work history, blood parameters, and anthropometric and audiometric test data were collected. Hearing thresholds were assessed at frequencies of 500, 1000, 2000, 3000, 4000, 6000 and 8000 Hz. Results. In total, 64.8% and 54.9% of hearing impairment degrees were observed in the left and right ears, respectively, and this difference was statistically significant. The hearing threshold in the left ear was higher at all frequencies. The maximum hearing loss was at 6000 Hz, followed by 4000 Hz. There was a significant relationship between hearing loss with age groups for right and left ears and type of car for left ear. Conclusion. The prevalence and severity of hearing loss in Shahroud drivers are high, and most hearing loss is observed in the left ear. Given that noise-induced hearing loss is an incurable condition and has a significant impact on individuals' quality of life and employment, drivers should be regularly screened for ear damage under the variables affecting hearing loss, and noise prevention training should be provided.