When infants talk, infants listen: pre‐babbling infants prefer listening to speech with infant vocal properties. Issue 2 (5th March 2015)

• Record Type: Journal Article
• Authors: Masapollo, Matthew; Polka, Linda; Ménard, Lucie
• Is Part Of: Developmental science. Volume 19:Issue 2(2016)
• Page Start: 318
• Page End: 328
• Publication Date: 2015-03-05
• Subjects: Developmental psychology -- Periodicals; Psychology, Comparative -- Periodicals; 155
• DOI: 10.1111/desc.12298
• Languages: English
• ISSNs: 1363-755X

Abstract

Abstract: To learn to produce speech, infants must effectively monitor and assess their own speech output. Yet very little is known about how infants perceive speech produced by an infant, which has higher voice pitch and formant frequencies compared to adult or child speech. Here, we tested whether pre‐babbling infants (at 4–6 months) prefer listening to vowel sounds with infant vocal properties over vowel sounds with adult vocal properties. A listening preference favoring infant vowels may derive from their higher voice pitch, which has been shown to attract infant attention in infant‐directed speech (IDS). In addition, infants' nascent articulatory abilities may induce a bias favoring infant speech given that 4‐ to 6‐month‐olds are beginning to produce vowel sounds. We created infant and adult /i/ ('ee') vowels using a production‐based synthesizer that simulates the act of speaking in talkers at different ages and then tested infants across four experiments using a sequential preferential listening task. The findings provide the first evidence that infants preferentially attend to vowel sounds with infant voice pitch and/or formants over vowel sounds with no infant‐like vocal properties, supporting the view that infants' production abilities influence how they process infant speech. The findings with respect to voice pitch also reveal parallels between IDS and infant speech, raising new questions about the role of this speech register in infant development. Research exploring the underpinnings and impact of this perceptual bias can expand our understanding of infant language development. Abstract : This is the first study to show that infants prefer listening to infant speech sounds over adult speech sounds. We indexed listening preferences in pre‐babbling infants by measuring by how long they fixated on a static visual pattern presented in tandem with either an infant vowel sound or an adult vowel sound, as shown in this figure. Probing further we found that infants prefer both the voice pitch (f0) and the formant structure of infant speech sounds. This perceptual bias favoring infant vocal properties may help to illuminate important aspects of infant speech and language development. There has been a great deal of research focused on how infants perceive speech produced by adults, but if we want to understand how infants learn to monitor and perceive the speech they themselves produce, we need to study how they perceive infant speech signals, too.