The seeds and spread of sound change: Individual differences in coarticulatory patterns

这个项目调查了当辅音和元音出现在其他声音旁边时，它们的发音的上下文变化。这就是所谓的“协同发音”。举个例子，当发音“bone”这个单词时，说话者在发音前面的“o”元音时，就开始了发出鼻音“n”所需的动作。这种发音重叠的哪些方面在说话者之间是普遍的，哪些方面在说话者之间是不同的？这个项目通过研究说美国英语的人在产生同一组单词时的协同发音模式是如何变化的来解决这个问题。由于协同发音提供了单词中即将到来的发音的预先信息，听者可以使用它来预测，从而更有效地理解语音。当使用协同发音来理解讲话时，听者如何适应不同说话者的差异？这个问题是通过调查听者在单词理解过程中如何追踪和使用相声者的协同发音变化来解决的。最后，协同发音在解释共同的历史声音变化方面发挥了突出作用，本项目探讨了协同发音变化在导致不同语言的历史变化中的作用。这项研究将有助于我们对言语的基本理解，并有助于更好地治疗言语和语言障碍。它还将有助于培养和指导下一代科学家（包括本科生、研究生和博士后研究员）。该项目的第一个目标是利用声学和感知评估来表征协同发音的个体差异。实验1确定了韵律组织、鼻腔协同发音、口腔发音和语音质量之间的特定关系，以便对100名美国英语说话者的协同发音产生语法进行类型化。实验2感知地定义了这些说话者产生的协同发音元音鼻化的语法规范的个体差异。我们的目标是使用与定义跨语言共发音变化相同的惯例来类型化跨说话人的变化，将个体间的共时共发音变化与跨语言的语音模式联系起来。我们的预测是，在不同语言中看到的协同发音模式的变化类型，也系统地存在于个体说话者身上。目的2：探讨说话人特定协同发音模式的知觉学习对听者声音变化机制的影响。实验3和4研究了对说话人特异性协同发音模式的知觉适应，探讨了听者对说话人特异性协同发音模式的适应如何成为语音化的一个整体机制。预测是，协同发音的感知学习是有帮助的，因为它允许听众既灵活又预测给定的说话者将如何产生一个单词。这种机制也可以整合到以听者为导向的声音变化机制中，以解释不同的协同发音模式是如何语音化的。该项目测试了基于听者的声音变化的新扩展，该扩展将感知适应整合到说话者特定的协同发音模式中，以解释新的协同发音模式是如何语音化的。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project investigates contextual variation in the pronunciation of consonants and vowels when they occur next to other sounds. This is known as 'coarticulation'. An example is that when pronouncing the word 'bone', speakers begin the movement needed to produce the nasal 'n' sound early, during the pronunciation of the preceding 'o' vowel. What aspects of this articulatory overlap are universal across speakers and what aspects can vary across speakers? This project addresses that question by examining how speakers of American English vary in their coarticulation patterns producing the same set of words. Since coarticulation provides advance information about upcoming sounds in the word, it can be used predictively by listeners to comprehend speech more efficiently. How do listeners adapt to cross-speaker variation when using coarticulation to comprehend speech? This question is addressed by investigating how listeners track and use cross-talker coarticulatory variation during word comprehension. Finally, coarticulation has played a prominent role in explaining common historical sound changes, and this project addresses the role of coarticulatory variation in leading to historical variation across languages. This research will contribute to our basic understanding of speech and can facilitate better treatment of speech and language disorders. It will also contribute to the training and mentoring of a future generation of scientists (including undergraduates, graduate students, and a postdoctoral researcher). The project's first objective is to characterize individual differences in coarticulation using acoustic and perceptual assessments. Experiment 1 identifies talker-specific relationships between prosodic organization, nasal-coarticulatory, oral articulations, and voice quality in order to typologize the coarticulation production grammars of 100 speakers of American English. Experiment 2 perceptually defines individual variation in the grammatical specification of coarticulatory vowel nasalization produced by these speakers. The goal is to typologize cross-speaker variation using the same conventions used to define cross-linguistic coarticulatory variation, relating synchronic coarticulatory variation across individuals to cross-linguistically phonologized phonetic patterns. The prediction is that the types of variation in produced coarticulatory patterns that are seen across languages also exist systematically across individual speakers. Objective 2 is to investigate the influence of perceptual learning of talker-specific coarticulatory patterns on listener-based sound change mechanisms. Experiments 3 and 4 investigate perceptual adaptation to talker-specific patterns of coarticulation, exploring how listener adaptation to talker-specific coarticulation patterns is an integral mechanism of phonologization. The prediction is that perceptual learning of coarticulation is helpful because it allows listeners to both be flexible and predict how a given talker is going to produce a word. This mechanism can also be integrated into listener-oriented mechanisms of sound change to explain how different coarticulation patterns phonologize. The project tests novel extensions of listener-based sound change accounts that integrates perceptual adaptation to talker-specific coarticulatory patterns in order to account for how novel coarticulatory patterns phonologize.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.