In a pulsation, threshold experiment the frequencies and intensities of the two tones in the “masker” were fixed and the frequency of the signal was varied. The plot of pulsation threshold versus signal frequency is called the pulsation‐threshold pattern of the “masker”. First the pulsation‐threshold pattern was measured when the “masker” contained only a 1000‐Hz tone. Then the patterns were measured for a 400‐Hz tone and for a 1500‐Hz tone. Finally, the pattern was measured when the masker contained both the 1000‐Hz tone and either the 400‐Hz tone or the 1500‐Hz tone. The 400‐Hz tone was able to reduce the pulsation thresholds around 1000‐Hz by 20 dB or more for each of the three subjects. The 1500‐Hz tone did not reduce the pulsation thresholds at 1000 Hz but did at 1100 Hz, i.e., on the high‐frequency tail of the 1000‐Hz pattern. Suppression is assumed to be the cause of these reductions. Thus one tone is able to suppress only part of the excitation pattern of another tone. Mutual suppression was also indicated for one subject. Relationships to partial masking will be discussed. [Work supported the NINCDS.]