Hearing in a 54- to 66-year-old population in northern Finland.

There are only a few large, population-based epidemiological studies on hearing impairment (HI) in adults. The objective of this study was to investigate the prevalence of HI and possible differences between ears in older adults. The subjects (n = 850), aged 54-66 years, were randomly sampled from the population register. A questionnaire survey, an otological examination, and pure-tone audiometry were performed. Another questionnaire was mailed to collect information on non-participants. The prevalence of HI averaged over the frequencies of 0.5, 1, 2, and 4 kHz for the better ear ≥20 dB HL was 26.7% (men: 36.8%, women: 18.4%). There was no difference between left and right ear pure-tone averages over the frequencies 0.5, 1, 2, and 4 kHz (PTA(0.5-4 kHz)), but a significant difference of -0.8 dB HL was found for the low frequencies 0.125, 0.25, and 0.5 kHz (PTA(0.125-0.5 kHz)), and 4.4 dB HL for the high frequencies over 4, 6, and 8 kHz (PTA(4-8 kHz)). In conclusion, HI was a highly prevalent finding in this age group.