Noise induced hearing loss- profile in military service

ABSTRACT

To describe the morbidity profile of soldiers being managed for disability due to sensorineural deafness as a result of noise induced hearing loss [NIHL] in military service. A descriptive study Department of statistics CMH Malir Cantt. Records of soldiers reporting for NIHL in CMH Malir Cantt during the period i.e January 2004 - January 2009 were included. All cases of sensorineural deafness either diagnosed for the first time or reporting in ENT OPD of CMH Malir Cantt for re-evaluation during the period i.e January 2004-January 2009 were included. The records of 70 such servicemen were available in statistics department of the hospital and were analysed to determine the profile of history and physical findings in all cases managed for sensorineural deafness. The total sample of cases studied included 70 servicemen. Their mean age group was 35.3 years, between 38-42 years of age while most vulnerable age group was between 33-37 years. A total of 41.4% of individuals had 10-15 years of service before this handicap was documented .While 47.1% accepted feeling this problem for 11-15 years, the period of observation in low medical category/handicap was less than 5 years in 54.3% of cases. As the most affected trades with max number of disabled soldiers, artillery and infantry had 40% each of all affected cases. Rinne's test was positive in 90% of them. Weber's test was lateralized to left ear indicating sensorinerual deafness in right ear in at least 82% of cases.PTA tests were conducted separately for both ears to determine the degree of hearing range loss. There was moderate hearing loss in the frequency range of 60-90 db in both ears in 47.1% of cases with hearing defect and severe hearing loss in range of >90 db in Right ear in 30.0% cases and in 15.7% of left ears checked. Noise induced hearing loss among relatively young [under 40 years of age] and otherwise healthy soldiers with around 5-10 years of service is a phenomenon that needs further research as an occupational health problem and all out efforts to reduce the incidence of this irreversible though preventable disease