Effect of click rate and delay on breakdown of the precedence effect

The precedence effect was tested as a function of echo-click delay and click rate after an abrupt switch in location between leading and lagging clicks. Click trains at three rates, 1/sec, 2/sec, and 4/sec, with delays ranging between 2 and 20 msec, were presented to subjects in an anechoic chamber. Duration of the click train after the switch in location was 12 sec, and echo click perceptibility was assessed throughout this period. The number of echo clicks heard was an increasing monotonic function of delay. The subjects reported a "fade-out" of echo clicks after a set number of clicks at each delay, regardless of rate. This result was interpreted as a buildup in inhibition of echoes produced by the ongoing click train. Suppression of echoes was stronger when the leading click originated from the right side than from the left side.