Prevalence of noise induced hearing loss among traffic police in Dhaka Metropolitan City.

The present study was done to determine the prevalence of noise induced hearing loss (NIHL) among the traffic police of Dhaka Metropolitan City. A cross sectional study was carried out among randomly selected 100 traffic police from January 2003 to June 2004, in the department of Department of Otolaryngology & Head-Neck Surgery, Bangabandhu Sheikh Mujib Medical University. Personal interview was taken from every respondent about the duration of exposure of noise (8 hours/day) in Dhaka City. Otological examination consists of 1) Otoscopy 2) Tuning fork test and 3) Pure tone audiometry. In this study 23 complaints of tinnitus or ringing in the ear and only 5% complaints of deafness. 24 respondents had mild to moderate high frequency sensorineural hearing loss, and affected mainly frequencies of 4-6 KHz. Among 20 mild hearing loss cases, 11/53(20.75%) have had duration of exposure between 6-10 years, 4/31 (12.9%) had duration of exposure between 11-15 years and 5/16(31.25%) had duration of exposure between 16-20 years. Among the 4 moderate hearing loss cases, 2/31(6.45%) had duration of exposure of 11-15 years and 2/16(12.5%) had 16-20 years of noise exposure in Dhaka Metropolitan City. Among those who had exposure 6-10 years, 20% shows mild sensorineural hearing loss and those had exposure 11-20 years, 28% had mild to moderate sensorineural hearing loss. In the present series it is concluded that 24% of the respondent having mild to moderate sensorineural hearing loss due to noise exposure which is related with the duration of exposure.