Aspects on personal noise protection.

Two groups of noise-exposed workers were compared with respect to their use of ear protectors. One group had a severe, noise-induced hearing loss; the other group had normal hearing. Both groups were composed of workers of similar age and total duration noise-exposure. It was found that those with normal hearing had used ear protectors considerably more than those with severe hearing loss. Interestingly, quite a few workers had normal hearing in spite of working in noise for many years without ear protectors. Also, quite a few workers had a severe hearing loss in spite of frequent use of ear protectors. The reasons for not using ear protectors were analysed as also was the condition of the protectors and frequency with which they were replaced. Plastic ear plugs were preferred by 44%, vinyl foam ear plugs by 26%, fibreglass down by 18%, and ear muffs by 11% of the workers. In general, the condition of the ear protectors was good. Surprisingly, one-third of the workers did not use ear protectors, many of them because they had not realized that the environment they worked in had a noise intensity level above the injury risk level.