Brief-tone frequency discrimination by children

This study investigated maturational changes in children's ability to discr iminate the frequency of short-duration tone pulses. Frequency difference l imens (DLs) were measured for digitally generated 1000-Hz tones with pulse durations of 200, 50, and :20 ms using a two-alternative, two-interval, for ced-choice procedure. Participants were 16 5-year-old children; 10 children each in the age categories of 7, 9, and 11 years; and a control group of 1 0 young adults. Eleven of the 5-year-old children were unable to learn the experimental task. All children in the three older groups and the adults su ccessfully completed the study. The five 5-year-old children who completed the task performed similarly to the 7-year-old children. All groups of part icipants showed an inverse relationship between duration of the signal and the size of the DL. The DLs at all three tone durations were significantly larger for the 7-year-old children than they were for the older children an d adults. There were no significant differences in DL size among the 9-year -old, 11-year-old, and adult subjects at any tone duration. These findings suggest that the sensory and/or cognitive skills required to discriminate t he Frequency of brief-duration tones may not reach maturity until after age 7 years.