Suppression and critical bands in band-limiting experiments.

Band-limiting experiments were performed at three noise spectrum levels (N0 = 25, 40, and 55 dB SPL) for forward, simultaneous, and backward masking. Threshold for a 2-kHz sinusoid decreased for masker bandwidths greater than a "critical bandwidth" in nonsimultaneous masking. These results are evidence for a suppression effect not observed in simultaneous masking; however, a qualitative model of suppression can account for the results in all three types of masking. In addition, the data for simultaneous masking support Fletcher's [Rev. Mod. Phys. 12, 47--61 (1940)] rectangular filter interpretation of the band-limiting experiment and are well described by a level-dependent critical band.