The effect of intensity and pitch accents on the perception of timing was examined in two experiments using a signal detection procedure. Analyses of sensitivity and response bias revealed opposite effects of intensity and pitch accents under similar conditions. Time intervals preceding intensity accents were perceived as longer, but time intervals preceding pitch accents were perceived as shorter. These results showed that listeners found it easier to detect timing variations that were contrary to expectations, as compared with variations that were consistent with expectations. In the present case, listeners should have expected shorter time intervals before intensity accents and longer intervals before pitch accents. The fact that the effects were observed with stimuli that had minimal musical structure demonstrated the contribution of psychoacoustic factors to such phenomena.