Dr.Manish Jacobson Biswas, Dr Brajendra Kumar


Exposure to excessive noise is the major avoidable cause of permanent hearing impairment. Worldwide, 16% of the disabling hearing loss in adults
is attributed to occupational noise, ranging from 7 to 21% in the various sub regions. Noise-induced hearing loss (NIHL) is bilateral and
symmetrical, usually affecting the higher frequencies (3k, 4k or 6k Hz) and then spreading to the lower frequencies (0.5k, 1k or 2k Hz). The major
industries responsible for excessive noise and exposing workers to hazardous levels of noise are textile, printing, saw mills, mining, etc. In India,
NIHL has been a compensable disease since 1948. Our objective of this study was to determine whether sound in the study areas was of sufficient
intensity to cause hearing loss and if so whether those exposed have been affected and to determine whether workers/employees in the study areas
were aware that sound can cause hearing loss and if so whether they knew that this can be prevented by ear protection. One hundred and fifty
workers from area A and fifty two employees from area B were selected for the study. A questionnaire was filled and had their hearing thresholds
measured by a pure tone audiometer machine.In both study areas the noise levels were above the safe limit of 85dB(A). In area A 28 workers and in
area B eight employees had noise induced hearing loss. In area A 81.1% of the workers and in area B 85% of the employees knew that noise causes
hearing loss. All workers/employees from both study areas knew that noise induced hearing loss could be prevented by some form of ear protection.
Workers/Employees exposed to noise above 85dB(A) will eventually develop hearing loss.


Audiogram,Hearing protectors, noise-induced hearing loss, occupational noise, prevalence

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