Figure 1.

Three dimensional representation of the stimuli used in the experiments. Temporal and spectral parameters of the signal and precursor are shown for the off-frequency (a) and on-frequency precursor (b) conditions. Masker level at threshold was the dependent variable in all conditions. In experiment 1, thresholds were measured for a series of masker frequencies (Note: only one frequency is displayed in the figure) to construct two PTCs, one for each precursor frequency. In experiment 2, thresholds for an off-frequency masker were measured for a series of signal levels to construct two GOM functions, one for each precursor frequency.