Pattern effects associated with the perception of the temporal microstructure of auditory signals were examined. Temporal changes, or gaps, were introduced into auditory interval patterns produced by a sequence of pulses. Discrimination thresholds for positive, and for negative, gaps were obtained as a function of the surrounding pattern of intervals. Gap thresholds increase with the slope of the surrounding interval pattern. Gap thresholds are smaller when the gap interval represents an extension, rather than a reversal, of the surrounding pattern. The results are in agreement with Heise and Miller’s thresholds of tonal isolation from repeated melodies, and with Mangelsdorf’s visual extrapolation thresholds of point-of-collision. The agreement of results from diverse test situations suggests a non-specifiC., general patterning effect upon discontinuity thresholds.