Discrimination of recycled word-length sequences
James A. Bashford, Richard M. Warrren · The Journal of the Acoustical Society of America · 1988
Earlier studies in this laboratory have dealt with the ability to distinguish between permuted orders using recycling or locked sequences of three of four items. More complex “Watson” sequences, presented as single bursts, typically of ten items, have been used to examine discrimination involving “word-length” patterns. The present study combines elements of both techniques, investigating the ability to discriminate minimal changes of order within recycled word-length sequences of 40 ms items: sinusoids (experiment 1); vowels (experiment 2); and frozen noise segments (experiment 3). Listeners made ABX judgments for pairs of ten-item sequences differing only in the ordering of two contiguous items. Pattern pools of 48 sequence pairs were employed in each experiment. This hybrid technique of recycling word-length sequences permits ready discrimination of permuted order: For example, naive listeners presented with tone sequences performed at levels well above chance at the outset of training and approached 96% accuracy in less than 100 trials. Special aspects of results obtained with sequences of vowels and frozen noise will be discussed. [Work supported by AFOSR.]