Experimental design. This figure illustrates the two different ABA sequences (Adaptation and Test) presented in Experiments 1 and 2, plotted as relative Frequency against relative Time. These sequences were presented with randomly-organized changes in position in uninterrupted trials. (A) Experiment-1; The Inter Stimulus Interval (ISI) between A and B tones in both sequences was fixed at 125 ms. Three different degrees of Δf (2, 4 and 10 semitones) were presented as either Adaptation or Test sequence. (B) Experiment-2; Δf between successive A and B tones was fixed at 6 semitones but the ISI varied between short (100 ms) and long (225 ms).