The interaction between backward and forward masking was investigated for conditions in which a signal is presented in the same ear as the masker, monotically, or in the contralateral ear, dichotically. The SPL of a signal required for equal detectability was determined in both monotic and dichotic backward and forward masking paradigms and in paradigms that combined backward and forward masking. In most cases, the combination of the various masking conditions produced a greater effect than either masker alone. Further investigation of the interaction of monotic forward and dichotic backward masking was conducted. Within intermasker intervals of 15, 25, and 45 msec signal SPL’s for equal detectability were determined for different temporal placements of the signal. The results indicated that when a contralateral backward masker is added to a forward masking paradigm, the signal must be increased by a constant amount to remain equally detectable. However, this constant increase was larger for the 15-msec masker separation than either the 25- or 45-msec separations.