Department of Linguistics, Simon Fraser University, Burnaby, BC, Canada.
Department of Psychology, Simon Fraser University, Burnaby, BC, Canada.
Dev Sci. 2022 Mar;25(2):e13180. doi: 10.1111/desc.13180. Epub 2021 Oct 21.
Infant-directed speech (IDS) is phonetically distinct from adult-directed speech (ADS): It is typically considered to have special prosody-like higher pitch and slower speaking rates-as well as unique speech sound properties, for example, more breathy, hyperarticulated, and/or variable consonant and vowel articulation. These phonetic features are widely observed in the IDS of caregivers from urbanized contexts who speak a handful of very well-researched languages. Yet studies with more diverse socio-cultural and linguistic samples show that this "typical" IDS prosody is not consistently observed across cultures. We extended cross-cultural work by examining IDS speech segment articulation, which-like prosody-is also thought to be a characteristic phonetic feature of IDS that might aid speech and language development. Here we asked whether IDS vowels have different articulatory features compared to ADS vowels in two distinct linguistic and socio-cultural contexts: urban English-speaking Canadian mothers, and rural Lenakel- and Southwest Tanna-speaking ni-Vanuatu mothers (n = 57, 20-46 years of age). Replicating prior work, Canadian mothers had more variable vowels in IDS compared to ADS, but also did not show clear register differences for breathiness or hyperarticulation. Vowels spoken by ni-Vanuatu mothers showed very distinct articulatory tendencies, using less variable (and less breathy) IDS vowels. Along with other work showing diversity in IDS phonetics across populations, this paper suggests that any understanding of how IDS might aid speech and language development are best examined through a culturally- and linguistically-specific lens.
婴儿导向语音（IDS）在语音上与成人导向语音（ADS）不同：它通常被认为具有特殊的韵律特征，如更高的音高和更慢的语速，以及独特的语音特征，例如更喘息、更清晰和/或可变的辅音和元音发音。这些语音特征在来自城市化背景的照顾者的 IDS 中广泛观察到，他们说少数几种研究得很好的语言。然而，具有更多社会文化和语言多样性样本的研究表明，这种“典型”的 IDS 韵律并不是在所有文化中都一致观察到的。我们通过检查 IDS 语音段发音扩展了跨文化工作，就像韵律一样，它也被认为是 IDS 的一个特征性语音特征，可能有助于言语和语言发展。在这里，我们询问 IDS 元音与 ADS 元音在两个不同的语言和社会文化背景下是否具有不同的发音特征：城市化的英语加拿大母亲，以及农村伦卡克尔和西南塔纳语的瓦努阿图母亲（n=57，20-46 岁）。与之前的工作一样，加拿大母亲在 IDS 中比 ADS 中的元音具有更大的可变性，但在喘息或清晰发音方面也没有明显的音域差异。瓦努阿图母亲所说的元音表现出非常明显的发音倾向，使用的 IDS 元音变化较小（喘息较少）。与其他表明人群中 IDS 语音学多样性的工作一起，本文表明，任何关于 IDS 如何帮助言语和语言发展的理解都最好通过文化和语言特定的视角来检验。
