Doctoral Dissertation Research: Articulation and Altered Auditory Feedback

每个人说话的方式各不相同。说话者在说话时会倾听自己的声音，他们不断地使用这种听觉反馈来纠正自己的讲话。本研究探讨影响说话者有效利用听觉反馈的两个因素：声道形状和母语。硬腭的形状，这是一个重要的因素之间的关系，清晰度和声学，将被用来作为衡量个人的解剖变异。在这个实验中，参与者说出包含感兴趣的语音的单词，他们的听觉反馈被计算机在真实的时间内改变，这样说话者听到自己说的话与他们实际产生的不同。以前的研究（例如Houde和Jordan 1998）表明，说话者会改变他们的发音以响应改变的听觉反馈，但不知道如何改变。在这里，同步超声成像的新功能将揭示说话者是如何补偿的，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。一个完整的典型言语模型可以作为理解言语障碍人群（如言语失用症或帕金森病患者）运动控制的基线。这项研究也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概括运动控制的讲话，而不局限于英语的结果。这项研究还解决了有关煽动语言变化的长期存在的问题。探索导致个体在言语产生中彼此根本不同的因素可能会解释为什么有些人可能比其他人更有可能促成导致声音变化的语言变异。

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.