Hierarchy of masking-level differences obtained for temporal masking t

Masked thresholds were obtained in four binaural conditions (N₀S₀, N₀S_m, N_πS₀, and N₀S_π)and in four temporal-masking conditions (simultaneous masking, forward masking, backward masking, and combined forward-backward masking). In all conditions Gaussian noise was the masker and was low-pass filtered at 5000 Hz and presented at 43-dB spectrum level. The signal was a 20-msec, 500-Hz tone gated with a 5-msec rise-decay time. The temporal interval between signal offset and masker onset (masker duration 500 msec) in the backward-masking condition was 1 msec. The temporal interval between masker offset and signal onset was 10 msec in the forward-masking condition. These same temporal intervals (but 250-msec maskers) were used in the combined forward-backward masking condition. The hierarcy of masking-level differences (MLD's) was the same in all of the temporal-masking procedures and matched that obtained in the simultaneous masking condition. More additional masking was obtained in the combined forward-backward masking condition for the N₀S₀ condition than for any of the binaural conditions (N₀S_m, N_vS₀, and N₀S_π).