Fusion of simultaneous tonal glides: the role of parallelness and simple frequency relations.

Adult listeners heard a pure-tone glide ("captor") repeatedly alternating with a complex glide consisting of three simultaneous pure-tone glides. One of the pure-tone glide components in the complex glide matched the captor glide in its frequency center, orientation, and direction. This component was referred to as the "target:’ The two other glides in the complex glide were referred to as "the frame:’ In some conditions, the captor captured the target glide perceptually into a sequential stream, causing it to be audible as a separate sound in the mixture. The slope of the target relative to the frame was varied. As the slope difference increased, the target became easier to capture. It was also more easily captured when it was parallel to the frame but did not fall into a simple harmonic relation with it.