Risk of hearing loss among teachers: a prospective study in the French CONSTANCES cohort

Abstract Background Teachers, a large professional group are regularly exposed to disturbing noise at work, particularly at the primary and secondary school levels, with elevated noise peaks that may endanger their hearing. Few studies have assessed auditory consequences of occupational noise exposure among teachers and none using longitudinal data. Methods Within the French national CONSTANCES cohort, Pure Tone Average (PTA) of the better ear was calculated based on air-conduction audiometry test (0.5, 1, 2 and 4 kHz), repeated approximately every five years (up to 3 tests from inclusion) among 14,375 teachers (primary n = 5812, secondary n = 6845, university n = 1718). We used mixed effects models adjusted for socio-demographic factors (age, sex, marital, family status, rural/urban residence, financial difficulties), lifestyle (smoking and body mass index) and health conditions (hypertension, diabetes, and cardiovascular diseases) to estimate mean parameters [95% confidence interval] of PTA changes in decibel Hearing Loss (dB HL) since enrolment, by teaching level (ref=university teachers) as a proxy of noise exposure. Results The study population consisted of 67% female teachers, with an average age of 44.2 years and with PTA of 12.3±7 dB HL. The mean follow-up time between the first and last audiogram was 5.3±1.5 years. Compared with university teachers, both primary and secondary school teachers had significantly poorer hearing at baseline (0.39 dB HL [0.00-0.77], p = 0.05 and 0.48 dB HL [0.12-0.85], p = 0.01 respectively). Additionally, primary school teachers experienced a slightly faster hearing deterioration over time compared to university teachers (0.11 dB HL per year [0.02-0.20], p = 0.01). Conclusions This large prospective study uncovers how primary and secondary school teachers may be particularly at risk of hearing loss. Given its detrimental impact on both ability to teach and quality of life, our results warrants further studies. Key messages • In this prospective study, primary school teachers were at higher risk of hearing loss compared to university teachers. • Better consideration of noise which can impact teachers’ job ability and quality of life is needed.