Figure 2 shows the distribution of subjects in various sections
of the lock factories. 27 subjects were employed at
power press unit ,29 at the lathe machine unit, 30 at the
grinder unit and 28 at the hand press unit. 30 subjects
were taken as control who were not exposed to industrial
noise. Figure 3 depicts the distribution of subjects according
to the duration of exposure to noise per day. 77 persons
were exposed for 7-8 hours,37 personswere exposed
for 9-10 hours with a break of half an hour to one hour for
lunch and one weekend holiday. Figure 4 shows the distribution
of subjects according to duration of service in
years. It shows that maximum numbers of subjects were
exposed to industrial noise for duration of 1-5 years. Table
II shows the hearing loss in relation with duration of
service. It is observed that as the duration of service increases,
percentage of hearing loss also increases. Figure
5 shows the noise level in the different units of lock factories
measured by LUTRONSL-4001 digital sound level
meter. It is seen that maximum noise was present in
power press unit followed by lathe machine, grinder unit
and hand press unit.