Child speech articulation development: Integrative and cross-language perspectives

目的：研究儿童言语表达行为的发展机制。在我之前对儿童语音产生的声学研究的基础上，本研究项目的短期目标是：1)描述儿童舌头运动控制随时间和跨语言的特征，以寻找控制儿童语音发音发展的潜在机制，而不管他们说的是哪种语言；2)确定舌头运动控制、手动运动、语音感知和语言环境之间的关系。长期目标是建立一个连贯和全面的语言习得理论，这是进化和生物学有效的信息。科学方法：为了实现这些目标，将使用超声成像技术和声学测量来检查说英语，日语或普通话的单语儿童的语音产生。超声技术提供了在发音过程中舌头位置和姿势的直接评估。当儿童进行语音生成实验时，他们的舌头表面曲率将被追踪，这些实验对他们的母语音素进行采样。儿童的语言也将同时录音，用于声学分析，这提供了舌头运动模式的另一个指标。超声和声学数据将随着时间的推移在个体内部、个体之间以及不同语言之间进行比较，以寻找共同的发育模式。除了发音测量，儿童的手部运动和灵巧性将被评估，以证实口头和手动运动控制之间的联系。然后，使用眼动追踪技术的语音感知实验来测量儿童感知语音区别的能力。最后但并非最不重要的是，孩子和他们的父母将使用LENA（语言环境分析）设备进行记录，该设备可以在一段时间内自动分析孩子的家庭语言环境。意义：说话是人类的决定性特征，但我们对这种能力如何在儿童中出现的理解有限。本研究旨在解决儿童舌头运动控制的个体发生及其与语言特定环境的相互作用这一难题。这项研究将阐明一般的语言进化理论，特别是音系理论，并具有重要的科学和技术意义。

Objectives: My research program investigates developmental mechanisms of child speech articulation behaviour. Building on my previous research on the acoustics of child speech production, the short term goals of this research program are to 1) characterize children's tongue motor control over time and across languages for the underlying mechanisms that govern speech articulation development in children regardless of the language they speak and to 2) identify the relationship between tongue motor control, manual movement, speech perception, and language environment. The long-term goal is to construct a coherent and comprehensive theory of speech acquisition that is evolutionarily informed and biologically valid. Scientific approach: To achieve these goals, speech production by monolingual children speaking English, Japanese, or Mandarin Chinese will be examined using ultrasound imaging technique and acoustic measurements. The ultrasound technique offers direct assessment on tongue position and posture during articulation processes. Children's tongue surface curvature will be traced while they are engaged in speech production experiments that sample the phoneme inventory of their native language. Children's speech will also be simultaneously audiorecorded for acoustic analysis, which provides another index of tongue movement pattern. Both the ultrasound and acoustic data will be compared over time within an individual, across individuals, and across languages for common developmental patterns. In addition to articulatory measurements, children's hand movement and dexterity will be evaluated to substantiate the link between oral and manual motor control. Children's ability to perceive speech sound distinctions will then be measured using speech perception experiments utilizing the eye-tracking techniques. Last but not least, children and their parents will be recorded using the LENA (Language Environment Analysis) device which affords automatic analysis of the child's home language environment over an extended period of time. Significance: Speech is the defining feature of humans, but our understanding of how this capacity emerges in children is limited. The proposed research program addresses a critical missing piece in deciphering this puzzle, namely, the ontogeny of children's tongue motor control and its interaction with language-specific environment. This research will illuminate evolutionary theory of language in general and of phonological theories in particular, as well as bear significant scientific and technological implications.