Beyond musical training: Individual influences on the perception of the speech-to-song illusion

Abstract

When a spoken phrase is repeated several times, listeners often report a perceptual illusion during which speech is transformed into song. The speech-to-song (STS) illusion is often attributed to prosodic elements of speech, though listeners can vary greatly in their STS experience. While previous research established robust links between music aptitude and STS, the present study asks whether other cognitive traits may also influence STS. Individual (in)sensitivity to nonverbal aspects of speech, specifically speech prosody, has been previously linked to autistic traits and emotional intelligence. We test whether the presence of autistic traits, the level of emotional intelligence and musical training, as well as syntactic complexity influence the likelihood, speed, and strength of STS among native British English listeners. The results provide evidence for the involvement of some but not all studied traits. We found sentence complexity to be interacting with a composite score of musical training, and emotional intelligence for the likelihood of STS, whereas sentence complexity influenced the strength of the transformation. These results suggest that individual listener variability may interact with the linguistic parameters of sentences in STS. Crucially, sensitivity to prosody through emotional intelligence or by the presence of autistic traits does not mediate the transformation.