As a means of partially distinguishing age effects and other risk factors in presbyacusis, hearing thresholds for 56- to 65-year-old participants screened for exclusion of selected risk factors were compared with thresholds for 48- to 55-year-old participants without the same risk factors. Hearing thresholds for both age groups were also compared with age-appropriate International Standards Organization (ISO) norms. Even after screening participants for exclusion of selected risk factors, differences in hearing sensitivity remained across age groups. Across the male and female groups, thresholds were generally better (lower) for 48 to 55 year olds than for 56 to 65 year olds. ISO norms generally underestimated the degree of hearing loss for participants of comparable age in the present study. The underestimation was small at lower test frequencies, was generally greater for men, and was largest at test frequencies above 2000 Hz.