Response behavior around auditory threshold

Normal adults, hearing-impaired preschool children, and normal-hearing mentally retarded children were assessed across repeated measures for auditory thresholds at 250 and 1000 Hz. Each subject's total performance across repeated measures was plotted by group by frequency relative to the last point of 100% correct response and interpolated thresholds. The results indicate that the steepness of the percentage of correct response performance curves and the variability of response performance above and below interpolated threshold were related to differences between the adult and child groups (mental age) and not between types of hearing populations (hearing sensitivity). The relationship between these results and experience with the signal is speculated.