Aspects of phonological fusion.

Phonological fusion occurs when the phonemes of two different speech stimuli are combined into a new percept that is longer and linguistically more complex than either of the two inputs. For example, when PAY is presented to one ear and LAY to the other, the subject often perceives PLAY. The present article is an investigation of the conditions necessary and sufficient for fusion to occur. The rules governing phonological fusion appear to be the same for synthetic and natural speech, but synthetic stimuli fuse more readily. Fusion occurs considerably more often in dichotic stimulus presentation than in binaural presentation. The phenomenon is remarkably tolerant of differences in relative onset time between the to-be-fused stimuli and of relative differences in fundamental frequency, intensity, and vocal tract configuration. Although phonological fusion is insensitive to such nonlinguistic stimulus parameters, it is sensitive to linguistic variations at the semantic, phonemic, and acoustic levels.