Listeners perceptually fuse the direct wave from a sound source with its reflections off nearby surfaces into a single sound image,located at or near the sound source (the precedence effect). This study investigated how a brief gap presented in the middle of either adirect wave or simulated reflection is incorporated into the fused image. For short (<9.5 ms) delays between the direct (leading) andreflected (lagging) waves, no sound was perceived from the direction of the lagging wave. For delays between 10 and 15 ms, bothsounds were perceived, but the gap was heard only on the leading side. When the gap was only in the correlated lagging sound atshort delays, it also was perceived as occurring on the leading side. Moreover, gap detection thresholds were the same for gaps in theleading and lagging sounds, suggesting that the perception of the gap was not suppressed, but rather incorporated into the leadingsound. Finally, scalp event-related potentials were not associated with the precedence effect until the gap occurred. This suggests thatcortical mechanisms are engaged to maintain fusion when attributes in direct or reflected waves change.