Psychophysical measurements relating suppression and combination tones.

Measurement of the combination tone 2f1-f2 with the pulsation-threshold technique yields a significantly lower value than measurement with the cancellation procedure. For three of four subjects, the difference between these two measures equals to amount of suppression produced at 2f1-f2 by the lower primary, f1. It appears that the cancellation procedure overestimates the combination-tone by f1. For a fixed level of f1, the level of the combination tone first increases, then decreases as the level of f2 is raised, for both cancellation and pulsation measures. The level of f2 at which these functions reach a peak is the same level at which f2 begins to suppress the lower primary, f1.