Better hearing in Norway. A comparison of two HUNT Cohorts 20 years apart

Objective: To obtain updated robust data on a age-specific prevalence of hearing loss in Norway and determine whether more recent birth cohorts have better hearing compared with earlier birth cohorts. Design: Cross-sectional analyzes of Norwegian representative demographic and audiometric data from the Nord-Trøndelag Health Study (HUNT)—HUNT2 Hearing (1996–1998) and HUNT4 Hearing (2017–2019), with the following distribution: HUNT2 Hearing (N=50,277, 53% women, aged 20 to 101 years, mean = 50.1, standard deviation = 16.9); HUNT4 Hearing (N=28,339, 56% women, aged 19 to 100 years, mean = 53.2, standard deviation = 16.9). Pure-tone hearing thresholds were estimated using linear and quantile regressions with age and cohort as explanatory variables. Prevalences were estimated using logistic regression models for different severities of hearing loss averaged over 0.5, 1, 2, and 4 kHz in the better ear (BE PTA4). We also estimated prevalences at the population-level of Norway in 1997 and 2018. Results: Disabling hearing loss (BE PTA4 ≥ 35 dB) was less prevalent in the more recent born cohort at all ages in both men and women (p < 0.0001), with the largest absolute decrease at age 75 in men and at age 85 in women. The age- and sex-adjusted prevalence of disabling hearing...