The forward and backward masking effect of a 20-mu s pulse was measured for
delays ranging From 0 to +/- 4 ms. Masking is not a monotonic function of
delay in either forward or backward masking. For two of the three observers
, the asymmetry in which forward masking exceeds that of backward masking i
s small for delays less than 500 mu s. The implications of the data for the
contribution of masking to the precedence effect are considered. (C) 1999
Elsevier Science B.V. All rights reserved.