Stream Segregation and the Illusion of Overlap

When two different sounds continuously alternate at high speed, they segregate into two perceptual streams. The present article shows that this segregation produces a loss of information regarding the sequential relations of the sounds so that they seem perceptually to be overlapped in time. The segregation (and its contribution to perceived overlap) is shown to increase with the perceptual difference between the sounds. The mapping from perceptual difference to perceived overlap is not simple, however, since perceived overlap can also be affected by "perceived auditory continuity," another perceptual effect that responds differently to the perceptual difference between the two sounds.