The Comparative Study of Subtle Deafness in Cosmopolitan, Town and Rural Population

Background: The presbycusis patients (usually beyond 50 years) come to us with much loss of hearing sensitivity. The deafness unperceived starts much earlier before their perception. Objectives: To identify the severity of the subtle deafness in the cosmopolitan, small town and rural areas. Materials and methods: We had selected the people with absolutely normal hearing (claimed by the subjects) between 21-50 years. They were confident of their hearing status, even on deep probing. We divided the people into three categories like cosmopolitan, small town and rural. We had selected the people of Mumbai under the cosmopolitan category. The audiological evaluation was carried out in sound treated room meeting the ANSI Standards of permissible ambient noise levels in sound treated room.Manual Pure Tone Audiometer in a two room set up that confirm to ANSI S-3.6-1996 standard was used. The instrument used for this study was calibrated ALPS AD 2100 audiometer with TDH 49 ear phones. Results: The cosmopolitan population were affected most. Later small town people and lastly rural area people were affected. In cosmopolitan population the 4 kHz was mostly affected, suggesting the significant impact of noise on their hearing. In town population also the 4 kHz is affected, but not to the extent of cosmopolitan people. The cosmopolitan people were affected worst among the three categories. And interestingly the small town population and rural population have almost the same hearing thresholds. Conclusion: The severity of subtle deafness is most in cosmopolitan, lesser in small town and least in rural population. The pure tone audiometry should be done in cosmopolitan people in early twenties, in small town people in early thirties and in rural population in early forties.