All stimuli in this example contain four identical frequency components (only for illustrative purposes: these were selected randomly in the experiments) with Fcoh = 1016.7 Hz, 2033.4 Hz, 3046.7 Hz, and 4066.8 Hz repeated over 6 chords and indicated by the black arrows. The figure is bound by a black rectangle in each stimulus. (A) Chord duration of 50 ms: stimulus comprises of 40 consecutive chords each of duration 50 ms with a total duration of 2000 ms. (B) Chord duration of 25 ms: stimulus comprises of 40 consecutive chords each of duration 25 ms with a total duration of 1000 ms. (C) Ramped figures: stimulus comprises of 40 consecutive chords each of duration 50 ms each (like A) but the frequency components comprising the figure increase in frequency in steps of 2*I or 5*I, where I = 1/24th of an octave, represents the resolution of the frequency pool. (D) Isolated figures: stimulus comprises only of the ‘figure present’ portion without any chords preceding or following the figure. The duration of the stimulus is given by the number of chords. (E) Chords interrupted by noise: stimulus comprises of 40 consecutive chords alternating with 40 chords comprising of loud, masking broadband white noise, each 50 ms in duration. In experiment 6b, the duration of the noise was varied from 100 ms to 500 ms (see ‘Materials and methods’).