Département de Linguistique et de traduction, Université de Montréal, 3150, rue Jean-Brillant, Montreal, Quebec, H3T 1N8, Canada.
Laboratoire de Phonétique et Phonologie, UMR7018, CNRS/Université Sorbonne-Nouvelle, 19 Rue des Bernardins, Paris, 75005, France.
J Acoust Soc Am. 2021 Dec;150(6):4429. doi: 10.1121/10.0008977.
Nursery rhymes, lullabies, or traditional stories are pieces of oral tradition that constitute an integral part of communication between caregivers and preverbal infants. Caregivers use a distinct acoustic style when singing or narrating to their infants. Unlike spontaneous infant-directed (ID) interactions, codified interactions benefit from highly stable acoustics due to their repetitive character. The aim of the study was to determine whether specific combinations of acoustic traits (i.e., vowel pitch, duration, spectral structure, and their variability) form characteristic "signatures" of different communicative dimensions during codified interactions, such as vocalization type, interactive stimulation, and infant-directedness. Bayesian analysis, applied to over 14 000 vowels from codified live interactions between mothers and their 6-months-old infants, showed that a few acoustic traits prominently characterize arousing vs calm interactions and sung vs spoken interactions. While pitch and duration and their variation played a prominent role in constituting these signatures, more linguistic aspects such as vowel clarity showed small or no effects. Infant-directedness was identifiable in a larger set of acoustic cues than the other dimensions. These findings provide insights into the functions of acoustic variation of ID communication and into the potential role of codified interactions for infants' learning about communicative intent and expressive forms typical of language and music.
童谣、摇篮曲或传统故事是口头传统的一部分，是照顾者与未语婴儿之间交流的一个组成部分。照顾者在唱歌或给婴儿讲故事时会使用独特的发声方式。与自发的婴儿指向（ID）互动不同，由于其重复性，有规则的互动得益于高度稳定的声学特性。本研究的目的是确定在有规则的互动中，特定的声学特征（即元音音高、时长、频谱结构及其可变性）组合是否会形成不同交际维度的特征“特征”，例如发声类型、互动刺激和婴儿指向。贝叶斯分析应用于来自母亲与其 6 个月大婴儿之间的有规则的现场互动中的超过 14000 个元音，结果表明，一些声学特征突出地描述了唤醒与平静的互动以及歌唱与口语的互动。虽然音高和时长及其变化在构成这些特征方面起着重要作用，但元音清晰度等更多的语言方面则显示出较小或没有影响。与其他维度相比，婴儿指向性可以用更多的声学线索来识别。这些发现为 ID 交流的声学变化的功能以及有规则的互动对婴儿学习语言和音乐中典型的交际意图和表达形式的潜在作用提供了一些见解。
