Masking and binaural masking-level differences (BMLDs) were measured using short 400 and 800 Hz test tones masked by uniform masking noise in both pre- and post-masking conditions. The BMLD shows the same dependence on the temporal position of the test signal as masking itself. Additional data produced with interrupted broad-band masker and with low-frequency tonal masker lead to the conclusion that more information about temporal structure is transmitted towards higher levels of processing than can be seen in simple post-masking experiments.