One of the most impairment aspect in occupational health is the study
   of noise induced hearing loss (NIHL) in noise exposed workers. The study
   was carried out to find out relation and a model between noise exposed
   workers and NIHL in 1997.

          To determine NIHL in the worker in loom-650, 45 workers having no
   confounding factors were choosen. All the study population were examined
   using audiometer.

          Result showed the SPL range was 70-105 dBA. The average of work
   experience were 10.3±3.5 and age 37.4±6.7 years. Correlation coefficient
   between job history and NIHL in the left ear was 0.7099 and  in the right ear
   was 0.7127. The Pearson’s correlation coefficient between left and right ear
   was positive and  equal to 0.69. The mean of NIHL between right and left
   ear was 14 dB which the  regression model predicts the limit of hearing loss
   in left ear is 4.5 years and in right ear is 3.8 years. Although the results
   showed loss of hearing begins in right ear, but left ear had more hearing loss
   with increasing of experience years. The danger limit for hearing of these
   workers (based on 25 dB loss), for left ear and right ear  were after 17 and
   20.7 years of work experience respectively.

          To prevent serious impairment in the workers hearing, it is suggested to
   consider the limit of 17 year's occupancy in forging as a base for changing
   the occupancy.