Purpose: To assess whether working in preschools increases the risk of hearing-related symptoms and whether age, occupational noise, and stressful working conditions affect the risk.
Methods: Questionnaire data on hearing-related symptoms were analysed in women aged 24-65 (4718 preschool teachers, and 4122 randomly selected general population controls). Prevalence and risk ratio (RR) of self-reported hearing loss, tinnitus, difficulty perceiving speech, hyperacusis and sound-induced auditory fatigue were assessed by comparing the cohorts in relation to age and self-reported occupational noise and stressful working conditions (effort-reward imbalance and emotional demands). RR was calculated using log-binomial regression models adjusted for age, education, income, smoking, hearing protection, and leisure noise. Incidence rates and incidence rate ratios (IRR) were calculated for retrospectively reported onset of all symptoms except sound-induced auditory fatigue.
Results: Compared to the controls, preschool teachers had overall more than twofold RR of sound-induced auditory fatigue (RR 2.4, 95% confidence interval 2.2-2.5) and hyperacusis (RR 2.3, 2.1-2.5) and almost twofold for difficulty perceiving speech (RR 1.9, 1.7-2.0). Preschool teachers had a threefold IRR of hyperacusis (IRR 3.1, 2.8-3.4) and twofold for difficulty perceiving speech (IRR 2.4, 2.2-2.6). Significantly although slightly less increased RR and IRR were observed for hearing loss and tinnitus. RR and IRR were generally still increased for preschool teachers when stratified by age and occupational exposure to noise and stress.
Conclusions: This large cohort study showed that working as preschool teacher increases the risk of self-reported hearing-related symptoms, indicating a need of preventative measures.
Keywords: Difficulty perceiving speech; Hyperacusis; Occupational noise; Sound-induced auditory fatigue; Stressful-working conditions; Tinnitus.