title: On the rhythm of infant- versus adult-directed speech in Australian English.
abstract: The findings are reported of an investigation into rhythmic differences between infant-directed speech (IDS) and adult-directed speech (ADS) in a corpus of utterances from Australian English mothers speaking to their infants and to another adult. Given the importance of rhythmic cues to stress and word-segmentation in English, the investigation focused on the extent to which IDS makes such cues salient. Two methods of analysis were used: one focused on segmental durational properties, using a variety of durational measures; the other focused on the prominence of vocalic/sonorant segments, as determined by their duration, intensity, pitch, and spectral balance, using individual measures as well as composite measures of prominence derived from auditory-model analyses. There were few IDS/ADS differences/trends on the individual measures, though mean pitch and pitch variability were higher in IDS than ADS, while IDS vowels showed more negative spectral tilt. However, the model-based analyses suggested that differences in the prominence of vowels/sonorant segments were reduced in IDS, with further analysis suggesting that pitch contributed little to prominence. The reduction in prominence contrasts may be due to the importance of mood-regulation in speech to young infants, and may suggest that infants rely on segmental cues to stress and word-segmentation.
authors.affiliation: Department of Psychology, Goldsmiths, University of London, London SE14 6NW, United Kingdom.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Lee
authors.affiliation: MARCS Institute, University of Western Sydney, Penrith, New South Wales 2571, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Kitamura
authors.affiliation: MARCS Institute, University of Western Sydney, Penrith, New South Wales 2571, Australia.
authors.forename: Denis
authors.initials: D
authors.lastname: Burnham
authors.affiliation: Faculty of Life Science, Stopford Building, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Neil P McAngus
authors.initials: NP
authors.lastname: Todd
mesh_terms: D000328:Adult; D000339:Affect; D001315:Australia; D002663:Child Language; D003463:Cues; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009034:Mother-Child Relations; D010507:Periodicity; D010700:Phonetics; D010898:Pitch Perception; D013060:Speech; D013067:Speech Perception; D013068:Speech Production Measurement; D013997:Time Factors; D014833:Voice Quality