Effect of practice on the identification of auditory sequences

Using a variant of the up-and-down method to establish duration thresholds for correct report of the order of sound sequences, six experiments were run with a practiced crew of three Ss. All showed striking improvement with practice, but substantial individual differences were observed. Two Ss found spaced sequences harder than simple cyclic ones and single presentations hardest of all, had increased difficulty when the component frequencies were brought closer together, and were disturbed by irregular timing. These variables made no difference to the third and most sensitive S, whose threshold reached 23 msec per component. All Ss displayed poorer performance if noise, additional signals, or a distrating activity occurred between the stimulus sequence and the response.