Deviant tone pattern detection is tested by graded practice then randomized no-feedback blocks.

Evidence

The practice block consisted of 10 trials. The first four were very easy with no transpositions and small within pattern intervals. The next four were slightly harder with two exact repeats of the pattern before two transpositions, with small within-pattern intervals and small transpositions. The final two examples were similar to trials in block 3 with small within-pattern intervals and small transpositions. … Participants were required to indicate using two on-screen response buttons (labelled ‘2nd Last’ and ‘Last’) whether the penultimate or last pattern was different from the rest. They were told that any difference was in the last interval of the pattern. … Following the practice block, participants were presented with seven test blocks, with no feedback. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5305