Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, 318 Barkley Center, Lincoln, NE 68583, USA.
J Speech Lang Hear Res. 2010 Dec;53(6):1529-42. doi: 10.1044/1092-4388(2010/09-0005). Epub 2010 Aug 10.
Although a growing body of literature has identified the positive effects of visual speech on speech and language learning, oral movements of infant-directed speech (IDS) have rarely been studied. This investigation used 3-dimensional motion capture technology to describe how mothers modify their lip movements when talking to their infants.
Lip movements were recorded from 25 mothers as they spoke to their infants and other adults. Lip shapes were analyzed for differences across speaking conditions. The maximum fundamental frequency, duration, acoustic intensity, and first and second formant frequency of each vowel also were measured.
Lip movements were significantly larger during IDS than during adult-directed speech, although the exaggerations were vowel specific. All of the vowels produced during IDS were characterized by an elevated vocal pitch and a slowed speaking rate when compared with vowels produced during adult-directed speech.
The pattern of lip-shape exaggerations did not provide support for the hypothesis that mothers produce exemplar visual models of vowels during IDS. Future work is required to determine whether the observed increases in vertical lip aperture engender visual and acoustic enhancements that facilitate the early learning of speech.
尽管越来越多的文献已经确定了视觉语音对言语和语言学习的积极影响，但对婴儿导向语音（IDS）的口腔运动却很少研究。本研究使用三维运动捕捉技术来描述母亲在与婴儿和其他成人交谈时如何改变嘴唇运动。
从 25 位母亲那里记录了她们与婴儿和其他成人交谈时的嘴唇运动。分析了嘴唇形状在不同说话条件下的差异。还测量了每个元音的最大基频、时长、声强以及第一和第二共振峰频率。
与成人导向言语相比，IDS 期间的嘴唇运动明显更大，尽管夸张是特定于元音的。与成人导向言语相比，IDS 期间产生的所有元音的特点是音高升高和说话速度减慢。
唇形夸张的模式并没有为这样一种假设提供支持，即母亲在 IDS 期间产生元音的范例视觉模型。需要进一步的工作来确定观察到的垂直唇开口增加是否会产生视觉和听觉增强效果，从而促进言语的早期学习。
