Abstract

Noise-induced hearing disorder has been thoroughly studied among workers in industry-like settings, but less so in female-dominated occupations. In Sweden, noise-related occupational disease among women are reported most frequently in the education sector.

We analysed questionnaires from 4,932 women with preschool teacher’s degree who have worked in preschool compared to 5,065 randomly selected women without preschool work-history (response rate 51% vs. 38%). The age range was 24–71 in both cohorts (mean 46 [SD 11] among preschool teachers and 51 [11] among controls). Prevalence and prevalence ratio in age-strata and Mantel-Haenszel pooled risk were calculated for hearing-related symptoms. Noise exposure was compared between the cohorts. A 5% level of significance was applied.

Occupational noise exposure and noise annoyance were significantly more common among teachers than controls: 75% vs.31% and 69% vs.26%, respectively. Still, significantly fewer teachers used hearing protection: 3% vs. 4%. Prevalence of hearing-related symptoms was much higher among teachers than controls: sound-induced auditory fatigue (71% [95% CI: 70–72] vs. 31% [30–32]), difficulty perceiving speech (46% [45–47] vs. 26% [25–27] and hyperacusis (38% [37–39] vs. 18% [17–19] and slightly higher for hearing loss (19% [18–20] vs. 17% [6–18] and tinnitus (19% [18–20] vs. 15% [14–16]. Teachers had a twofold risk of sound-induced auditory fatigue (PR-MH 2.2 [95% CI: 2.1–2.3] and hyperacusis (PR-MH 2.1 [1.9–2.2] compared to controls, when adjusted for age. The risk was also increased for difficulty perceiving speech (PR-MH 1.8 [1.7–1.9], tinnitus (PR-MH 1.4 [1.3–1.6] and hearing loss (PR-MH 1.4 [1.3–1.5]. Mean age of onset was significantly lower among teachers for all symptoms, except for hyperacusis (p = 0.902). Leisure-noise was significantly more common among controls. Family history of hearing loss did not differ (p = 0.411).

The study is the first to show that preschool teachers have an increased risk of hearing-related symptoms, which may be caused by the work environment.