Hearing threshold distribution and effect of screening in a population-based German sample

Objective: To establish the status of hearing in adults in Germany and the effects of screening for noise, tinnitus, ear diseases, and general health on the distribution of hearing threshold levels (HTL) Design: A cross-sectional epidemiological study conducted between 2010 and 2012 in two middle-sized cities. Study sample: A total of 1903 adults aged 18 to 97 years from a randomized sample drawn from the local registration offices and stratified for age and gender. Results: Dispersion and distribution of HTL data observed in the population-based sample are well in line with international results. However, median HTL tend to be better than in most recent international studies. Screening for “otological normality” improves the median HTL overall by 3 dB in males and 1 dB in females. This effect is strongly age-dependent in males and far less pronounced in females. While by and large HTL medians of females in the screened sample meet the values expected by ISO 7029:2000, HTL medians of males in middle and higher age cohorts are better than expected, especially in the frequencies above 2 kHz. Conclusions: This study supports international findings that in males, the age-related decrease in hearing sensitivity at high frequencies is smaller than described by ISO 7029:2000.