Prevalence of Noise Induced Hearing Loss in Indian Air Force Personnel

摘要

Background: Noise exposure is an inherent part of duty of the aircrew and maintenance staff in the Indian Air Force (IAF). Anaudiometric survey of IAF personnel was carried out to analyze the prevalence and severity of noise induced hearing loss (NIHL).Methods: An audiometric study of 1000 IAF personnel of various trades, age and exposure groups were carried out at an operationalbase. Age related correction of 5 dB per decade was applied for personnel above SO years of age. Personal factors like smoking,blood group and use of ear defenders were analysed for their effect on the prevalence of NIHL.Result: The study revealed an overall incidence of NIHL of 22.9 % in the personnel with a higher prevalence among the technicaltrades (26.18 %) as compared to non technical trades (12.5 %). There was a significant increase in prevalence of hearing loss withduration of exposure with 50.8% of personnel above 30 years of exposure having hearing loss. A higher incidence of hearing losswas observed in personnel of blood group O and smokers whereas use of ear defenders was protective.Conclusion: The study reveals a significantly increased prevalence of NIHL among the technical trades of the IAF personnel. Thedeleterious effects of smoking and protective effect of regular use of ear defenders are emphasized.