Maternal and paternal infant directed speech is modulated by the child’s age in in two and three person interactions

Article Article scientifique Article Maternal and paternal infant directed speech is modulated by the child’s age in in two and three person interactions eng 2025-04-19 author Filippa Manuela 0000-0002-1310-8008 Department of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland. manuela.filippa@unige.ch.,Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland. manuela.filippa@unige.ch. 890536 Section de psychologie (PSICO) author Tissot Hervé Department of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland.,Department of Psychiatry, Lausanne University Hospital, Lausanne, Switzerland. 701977 Section de psychologie (PSICO) author Mancinelli Tiffany Department of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland. 773357 author Favez Nicolas 0000-0003-1744-7602 Department of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland.,Department of Psychiatry, Lausanne University Hospital, Lausanne, Switzerland. 23914 Section de psychologie (PSICO) author Grandjean Didier Maurice Department of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland.,Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland. 502006 Section de psychologie (PSICO) 10.1038/s41598-025-98047-3 40253572 2045-2322 PMC12009295 https://www.nature.com/articles/s41598-025-98047-3 Prosody in infant-directed speech (IDS) serves important functions for the infant's attention, regulation, and emotional expression. However, how the structural characteristics of this vocal signal are influenced by the presence or absence of one or two parents at different infant ages remains under-investigated. This study aimed to identify the acoustic characteristics of parental vocalizations in 69 families during specific phases of the Lausanne Trilogue Play (LTP) setting. Vocalizations were analyzed in both two-person contexts (mother-baby or father-baby interacting with the infant individually) and three-person contexts (mother-baby or father-baby interactions in the presence of the other parent) at three time points: when the infant was 3, 9, and 18 months old. Videos of interactions were coded, and the parental vocalizations were extracted. Five components of acoustic features related to the prosodic aspects of speech were extracted for subsequent analysis: intensity and its variability, pitch and pitch variability, formant amplitude, the intensity of specific speech frequency bands affecting sound timbre, and the rate of voiced and unvoiced segments per second. The study demonstrated a main effect of infant age on parental acoustic prosodic characteristics, along with significant interactions between infant age and interaction context (two- versus three-person) and between infant age and parental role (mother versus father). Across contexts and parental roles, intensity, pitch, and their variability consistently increased from 3 to 9 months. By 9 months, distinct prosodic patterns emerged, including a reduced syllable rate and formant amplitude, along with an increase in pauses. The mother's voice exhibited a steady increase in intensity, as well as in pitch and intensity variability. Interestingly, when comparing parents across the two contexts, IDS in the three-person context is characterized by a higher rate of syllables and fewer pauses, with the most pronounced changes observed at 9 months of age. The development of prosodic characteristics in IDS is not constant across age and it is influenced by the complex interactions between age phases, parental gender, and contextual factors, with a dynamic adaptation of the communication strategies in three-person contexts. The current study underscores the importance of taking a comprehensive perspective in analyzing infant-directed speech within an interactive context involving both fathers and mothers in two- and three-person settings. Emotional prosody Infant-directed speech Lausanne trilogue play Dewey 150 Swiss National Science Foundation Family alliance as a moderator factor between maternal depressive state in the postpartum period and child outcomes: a developmental study of family processes 125493 CH Projects 108 Section de psychologie 71 false 594 Neuroscience de l'émotion et dynamiques affectives (NEAD) 1241 Affective sciences Scientific reports 15 1 e63eb0fc-10ad-45fe-94a9-08e8d90da636 Article (Published version) Public Article_scientifique_from_crossref.pdf 1644433 application/pdf 7a5a1d5df9ffd7dbbd9b8cdf7ceca84efdcb8dd6c4f862721e35aa8c66e9c74b openAccess Faculté de psychologie et des sciences de l'éducation / Section de psychologie

Title	Published in	Year	Views	Downloads

Maternal and paternal infant directed speech is modulated by the child’s age in in two and three person interactions	Scientific reports	2025	64	344
Étude des variations prosodiques paternelle et maternelle durant le jeu trilogique de Lausanne, et lien avec l'alliance parentale		2020	211	7

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Mancinelli, Tiffany