Doctoral Dissertation Research: Articulation and Altered Auditory Feedback

每个人说话的方式各不相同。演讲者在讲话时会倾听自己的声音，他们会不断地使用这种听觉反馈来纠正自己的讲话。这个项目考察了两个影响说话人有效使用这种听觉反馈的因素：声道形状和母语。硬腭的形状是发音和声学关系中的一个重要因素，它将被用作个体解剖差异的衡量标准。研究人员比较了美式英语和泰米尔语中发音相似、发音差异相似的两种发音，以测试母语的作用。在这项实验中，参与者说出包含感兴趣语音的单词，他们的听觉反馈被计算机实时改变，这样说话者听到的话与他们实际说出的话不同。以前的研究(如Houde和Jordan 1998)表明说话人的发音会随着听觉反馈的改变而改变，但目前还不清楚是如何改变的。在这里，新增加的同步超声成像将揭示扬声器是如何补偿的。这些研究的结果将改进我们在说话时如何修改运动计划的模型。典型言语的完整模型是理解言语障碍人群运动控制的基线，如言语失用症或帕金森氏症患者。这项研究还将有助于我们理解听觉反馈在运动控制中的作用，这对听力损失的人有直接的影响。比较英语和泰米尔语有助于支持关于言语中运动控制的概括，而不是将结果局限于英语。这项研究还解决了有关语言变化的长期存在的问题。探索导致个人在语音产生上存在根本差异的因素，可能会为为什么一些人比其他人更有可能对导致语音变化的语言变异池做出贡献提供一个解释。

Individuals vary from one another in how they speak. Speakers listen to themselves while talking, and they constantly use this auditory feedback to correct their speech. This project examines two factors that influence the way that speakers are able to effectively use this auditory feedback: vocal tract shape and native language. The shape of the hard palate, which is an important factor in the relationship between articulation and acoustics, will be used as a measure of individual anatomical variation. Two similar sounds with comparable articulatory variation in American English and Tamil are compared to test the role of native language.In this experiment, participants say words containing the speech sounds of interest, and their auditory feedback is altered in real time by a computer so speakers hear themselves saying something different from what they actually produced. Previous studies (e.g. Houde and Jordan 1998) show that speakers change their articulation in response to altered auditory feedback, but it is not known how. Here, the novel addition of simultaneous ultrasound imaging will reveal how speakers compensate.The results of these studies stand to improve models of how we modify our motor plans while speaking. A complete model of typical speech serves as a baseline for understanding motor control in populations with disordered speech, such as those with apraxia of speech or Parkinson's Disease. This research will also contribute to our understanding of the role of auditory feedback in motor control, which has direct implications for people with hearing loss. Comparing English and Tamil helps to support generalizations about motor control in speech without confining results to English alone. This research also addresses long-standing questions concerning the instigation of language change. Exploring the factors that cause individuals to be fundamentally differently from each other in their speech production may provide an explanation for why some individuals might be more likely than others to contribute to the pool of language variation that results in sound change.