Noise exposure, noise annoyance, use of hearing protection devices and distress among blue-collar workers

This study tested the hypotheses that, in high noise levels [> or = 85 dB(A)], hearing protection devices are used largely by workers sensitive to noise, as reflected by reports of noise annoyance, and that the usage would reduce distress symptoms.

Data collected from 1587 healthy male blue-collar workers included noise exposure level, noise annoyance, use of hearing protection devices, distress symptoms (somatic complaints and poststress irritability), and possible confounding by age, education and ethnic origin.

Multiple logistic regression results indicated that the use of hearing protection devices was related to noise exposure level [odds ratio (OR) 2.94, 95% confidence interval (95% CI) 2.58--3.30], but more so to high noise annoyance (OR 3.03, 95% CI 2.77--3.29), even after control for age, education, and ethnic origin. No interaction was found between noise level and noise annoyance. These findings highlight the contribution of noise annoyance to the use of hearing protection devices. Of the 42.6% of workers using hearing protection devices in the presence of high ambient noise, 60% were highly annoyed. Noise-annoyed workers also tended to wear hearing protection devices even in low noise levels. The use of hearing protection devices was associated with lower distress symptoms among the low and moderately annoyed workers, but among the highly annoyed workers the reverse was true.

Thus, for the highly annoyed workers, the use of hearing protection devices was perhaps an additional source of stress. One immediate implication of this study is that future intervention procedures should focus on unannoyed workers who tend to use hearing protection devices less.