Noise sensitivity and hearing disability.

The aim of this study was to investigate the association of noise sensitivity with self-reported hearing disability and hearing levels, with consideration of the role of self-reported history of noise exposure and use of hearing protectors. The study is based on the Finnish Twin Cohort. In 1988, a noise questionnaire was sent to 1005 twin pairs, 1495 individuals (688 men, 807 women) replied. The age range was 31-88 years. Information on some potential confounders was obtained from the questionnaire in 1981 for the same individuals. A subsample of thirty-eight elderly women with noise sensitivity response from 1988 had audiometry data from 2000 to 2001. Noise sensitivity was associated with self-reported hearing disability among all subjects [odds ratio (OR) 1.55, 95% confidence interval (CI) 1.14-2.12] and among women (OR 1.90, 95% CI 1.19-3.04), but no-more significantly among men (OR 1.31, 95% CI 0.86-1.98). The association was primarily seen among younger subjects (50 years or less). The difference between noise sensitive and non-noise sensitive elderly women in the average of thresholds at frequencies of 0.5-4 kHz in the better ear was not significant (Pr = 0.18). Noise sensitivity did not modify the association of hearing disability with the self-reported history of occupational noise exposure. Noise sensitivity was associated with the use of hearing protectors at work. The study shows the importance of recognizing the noise sensitive in noise effect studies, since sensitivity in annoyance has implications in most of the effect categories.