An American survey has found that the prevalence of measured hearing loss among noise-exposed factory workers was 42%.
At the same time, 76% of the workers reported their hearing ability as good or excellent. The difference in perceived hearing ability was significant at each tested frequency between those with and without measured hearing loss. Thus, self-reported hearing ability was poorly-related to results of the audiometry.
In the survey, hearing loss was defined as above 25dB hearing loss at 2, 3 and 4 kHz in either ear.
Noise represents one of the most common occupational health hazards.
Increased attention needed
Although this group of workers was employed in a regulated environment and served by a hearing conservation program, hearing loss was highly prevalent. The researchers found that their results, together with national prevalence estimates, support the need for evaluation of hearing conservation programs and increased focus on reducing adult hearing loss in the US.
The data was collected as part of an intervention study promoting hearing protector use among 2,691 workers at an automotive factory in the Midwest in the US. The study was carried out by the University of Michigan, School of Nursing in the US.