This longitudinal study investigated modifications in lexical tones and intonation in Cantonese infant-directed speech (IDS) to children aged 15 and 23 months. The results showed that to children at both ages, mothers increased intonational pitch height and pitch variability across utterances, and produced lexical tones with generally larger tonal space and greater intra-talker tone variation within categories in IDS compared to adult-directed speech. No significant changes were found in either lexical tones or intonation in IDS between the two ages. In addition, positive correlations were found between the degree of age-related changes in tonal space and intonational exaggerations in IDS as children grow older. The findings were discussed with a focus on the co-occurrence of an increase in tone variation along with tonal space expansion, the age-related changes in lexical tones and intonation, and the associations between the lexical and prosodic pitch modifications.

中文翻译：

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广东话婴儿定向言语中词汇声调和语调与年龄相关的变化：一项纵向研究


这项纵向研究调查了 15 个月和 23 个月儿童的粤语婴儿定向言语 (IDS) 中词汇声调和语调的变化。结果表明，对于两个年龄段的孩子，与成人指导的语音相比，母亲增加了语调的音调高度和不同话语的音调变异性，并且在 IDS 类别中产生的词汇音调通常具有更大的音调空间和更大的说话者内部音调变化。两个年龄段之间 IDS 的词汇声调或语调均未发现显着变化。此外，随着儿童年龄的增长，IDS 中音调空间与年龄相关的变化程度与语调夸张之间存在正相关关系。讨论的重点是声调变化增加与声调空间扩展的同时发生、词汇声调和语调中与年龄相关的变化，以及词汇和韵律音高修改之间的关联。