title: The Speech-to-Song Illusion Is Reduced in Speakers of Tonal (vs. Non-Tonal) Languages.
abstract: The speech-to-song illusion has attracted interest as a probe of the perceptual interface between language and music. One might anticipate differential speech-to-song effects in tonal vs. non-tonal languages, since these language classes differ importantly in the linguistic value they assign to tones. Here we addressed this issue for the first time in a cohort of 20 healthy younger adults whose native language was either tonal (Thai, Mandarin) or non-tonal (German, Italian) and all of whom were also fluent in English. All participants were assessed using a protocol designed to induce the speech-to-song illusion on speech excerpts presented in each of the five study languages. Over the combined participant group, there was evidence of a speech-to-song illusion effect for all language stimuli and the extent to which individual participants rated stimuli as "song-like" at baseline was significantly positively correlated with the strength of the speech-to-song effect. However, tonal and non-tonal language stimuli elicited comparable speech-to-song effects and no acoustic language parameter was found to predict the effect. Examining the effect of the listener's native language, tonal language native speakers experienced significantly weaker speech-to-song effects than non-tonal native speakers across languages. Both non-tonal native language and inability to understand the stimulus language significantly predicted the speech-to-song illusion. These findings together suggest that relative propensity to perceive prosodic structures as inherently linguistic vs. musical may modulate the speech-to-song illusion.
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College LondonLondon, UK; Department of Psychiatry, Faculty of Medicine, Thammasat UniversityBangkok, Thailand.
authors.forename: Kankamol
authors.initials: K
authors.lastname: Jaisin
authors.affiliation: Department of Global Health and Development, London School of Hygiene and Tropical MedicineLondon, UK; International Health Policy Program, Ministry of Public HealthBangkok, Thailand.
authors.forename: Rapeepong
authors.initials: R
authors.lastname: Suphanchaimat
authors.affiliation: Department of Speech, Hearing and Phonetic Sciences, Faculty of Brain Sciences, University College London London, UK.
authors.forename: Mauricio A
authors.initials: MA
authors.lastname: Figueroa Candia
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London London, UK.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Warren
keywords: bilingual; music; prosody; speech-to-song illusion; tonal language