Discrimination of restrictions in sequentially blocked auditory displays: Shifting block designs

Finite-state Markov sequences were generated by a digital computer, translated to electrical pulse trains, and converted to sound by earphones. The sequences were constrained in terms of the maximum number of occurrences of any state within any block of successive items. The discriminability among such sequences was measured in terms of the threshold interstate interval difference that is required to achieve a given level of discrimination among the sequences. These thresholds are closely related to the number of selections available to the source generator for each position of the sequence.