Speech-to-song transformation in perception and production

The speech-to-song transformation is an illusion in which certain spoken phrases are perceived as more song-like after being repeated several times. The present study addresses whether this perceptual transformation leads to a corresponding change in how accurately participants imitate pitch/time patterns in speech. We used illusion-inducing (illusion stimuli) and non-inducing (control stimuli) spoken phrases as stimuli. In each trial, one stimulus was presented eight times in succession. Participants were asked to reproduce the phrase and rate how music-like the phrase sounded after the first and final (eighth) repetitions. The ratings of illusion stimuli reflected more song-like perception after the final repetition than the first repetition, but the ratings of control stimuli did not change over repetitions. The results from imitative production mirrored the perceptual effects: pitch matching of illusion stimuli improved from the first to the final repetition, but pitch matching of control stimuli did not improve. These findings suggest a consistent pattern of speech-to-song transformation in both perception and production, suggesting that distinctions between music and language may be more malleable than originally thought both in perception and production.