Age changes in pure-tone hearing thresholds in a longitudinal study of normal human aging

Hearing thresholds were obtained on 813 adult males (20-95 years) measured at 11 frequencies ranging from 0.125-8 kHz from pure-tone audiograms collected over a 20-year period from 1968 to 1987. Audiograms taken at two to six different ages spanning a maximum observation period of 15 years were obtained for each male belonging to one of seven different age groups (20,30,...,80 years) based on the age of initial observation. The males were participants in the Baltimore Longitudinal study of Aging (BLSA), a multidisciplinary community-based study of normal human aging. Changes in hearing thresholds occurred in all age groups during the 15-year follow-up period. For example, at 0.5 and 8 kHz for combined left and right ears there was an average longitudinal loss of 5.7-7.6 and 5.1-21.1 dB, respectively, for 20-year-olds, 10.0-12.7 and 35.2-53.0 dB for 50-year-olds, and 22.9-48.5 and 69.0-84.5 dB for 80-year-olds. As in results from previous cross-sectional studies, hearing loss in the males 70 years and older is greatest at the highest frequencies. The rate of change for these older males is faster in the speech-range frequencies 0.5-2 kHz than in the higher frequencies, since their hearing has already diminished at the high frequencies.