Panels present, by decade, the median observed hearing threshold data for the final screened sample (filled triangles) and the thresholds estimated by the mixed-effects models (open squares). The ISO-7029 (2000) median hearing threshold data (open circles) are presented for comparison. The numbers of observations contributing to the thresholds for each frequency for each age group are listed in Table V.
The panels present, by decades 30–70, the progression of the mixed-effects model (estimated) audiometric thresholds (in dB HL, ANSI, 1989) in 3-year increments (total of 6 per panel: i.e., 30, 33, 36, 39, 42, 45) spanning 15 years. The top line in each panel shows the estimated initial visit thresholds for the ages 30s, 40s,…70s, and also appears in the 30s–70s panel (bottom right) to summarize the findings for each decade grouping.
The percent of modeled right-ear thresholds (ANSI, 1989) for age decade groups using first visit estimated audiometric thresholds only.
The average estimated rate of change (in dB per year) of hearing thresholds as a function of age for each audiometric frequency.
The longitudinal (filled circles) and cross-sectional (CS; open circles) average annual rate of change (ordinate) of hearing threshold for each frequency as a function of age (abscissa). The gray-shaded circles for CS data at 2.0 through 8.0 kHz for the 70 year olds represent the larger differences in annual rates of change for this age group.
Characteristics (mean, minimum, and maximum) of the longitudinal follow-up for men in each age group at the first visit for the final screened sample .
Distribution of the number of years the men were followed from the starting age interval.
Occupation distributions at the first visit for the men in the final screened sample .
Fixed effects coefficients of the final mixed model.
The , , and percentile thresholds (dB HL, ANSI, 1989) calculated from the observed data. Refer to Figure 1 for the median observed hearing threshold data (filled triangles).
Mean hearing thresholds (in dB HL, ANSI, 1989) and standard errors estimated by the mixed-effects model for men aged 30 to 70 years at their first visit and their ages at longitudinal follow-up (5-year increments). The thresholds in boldface indicate the age at which the threshold first exceeded 25 dB HL, or 'normal hearing sensitivity', for the given frequency.
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