Previous research on infant-directed speech (IDS) and its role in infants’ language development has largely focused on mothers, with fathers being investigated scarcely. Here we examine the acoustics of IDS as compared to adult-directed speech (ADS) in Norwegian mothers and fathers to 8-month-old infants, and whether these relate to direct (eye-tracking) and indirect (parental report) measures of infants’ word comprehension. Forty-five parent-infant dyads participated in the study. Parents (24 mothers, 21 fathers) were recorded reading a picture book to their infant (IDS), and to an experimenter (ADS), ensuring identical linguistic context across speakers and registers. Results showed that both mothers’ and fathers’ IDS had exaggerated prosody, expanded vowel spaces, as well as more variable and less distinct vowels. We found no evidence that acoustic features of parents’ speech were associated with infants’ word comprehension. Potential reasons for the lack of such a relationship are discussed.

中文翻译：

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母亲和父亲针对婴儿的言语具有相似的声学特性，但这些与 8 个月大婴儿的单词理解能力的直接或间接测量无关

此前关于婴儿定向言语（IDS）及其在婴儿语言发展中的作用的研究主要集中在母亲身上，而对父亲的研究很少。在这里，我们检查了挪威母亲和父亲对 8 个月大婴儿的 IDS 声学效果与成人定向言语 (ADS) 的比较，以及这些是否与婴儿的直接（眼动追踪）和间接（父母报告）测量相关’字的理解。四十五个父母-婴儿二人组参与了这项研究。记录了父母（24 名母亲，21 名父亲）向婴儿 (IDS) 和实验者 (ADS) 朗读图画书的情况，确保不同说话者和语域的语言背景相同。结果显示，母亲和父亲的 IDS 都有夸张的韵律、扩大的元音空间以及更多变化和不太明显的元音。我们没有发现任何证据表明父母言语的声学特征与婴儿的单词理解有关。讨论了缺乏这种关系的潜在原因。