The sound-to-music illusion: Repetition can musicalize nonspeech sounds

The speech-to-song illusion tracks a perceptual transformation across repetitions where a stimulus that originally sounded like speech comes to sound like song. This article examines whether the illusion also generalizes to other kinds of nonspeech sounds. Participants heard each of 20 environmental sound clips repeated in either original or jumbled form. They rated the musicality of the clips on a 5-point scale where 1 represented sounds exactly like environmental sound and 5 sounds exactly like music. Average ratings increased significantly across repetitions, suggesting that the speech-to-song illusion is one form of a more general sound-to-music illusion produced by repetition. This illusion occurred regardless of whether the clips were repeated in original or jumbled form, marking a difference compared to speech, for which the illusion only occurred if the repetitions were exact.