1. a phenomenon in which perception of the source of a sound precludes or inteferes with attention to reflections of this sound from different locations. For example, if a sound is produced by a particular source and is then reflected off the walls, the listener only perceives the first source, provided that the sound from the second source arrives within a short period of time (less than 70 ms).

2. the tendency for global features of a stimulus to dominate local features in performance tasks.