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

这个项目调查辅音和元音与其他发音相邻时发音的语境变化。这就是所谓的“协同发音”。一个例子是，当发音单词‘bone’时，说话者在发音前一个元音‘o’的过程中，会提前开始发出鼻音‘n’所需的动作。这种发音重叠的哪些方面在发言者之间是通用的，哪些方面可以在不同的发言者之间有所不同？这个项目通过研究说美式英语的人在产生相同单词时的协同发音模式的不同来解决这个问题。由于协同发音提供了有关单词中即将到来的声音的提前信息，因此听者可以预测性地使用协同发音来更有效地理解言语。当使用协同发音来理解语言时，听者如何适应跨说话人的变化？这个问题是通过调查听者在单词理解过程中如何跟踪和使用交叉说话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发音变化方面发挥了突出的作用，本项目讨论了协同发音变异在导致语言之间的历史差异方面的作用。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。它还将有助于培训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知觉评估来表征协同发音中的个体差异。实验一确定了韵律组织、鼻腔协同发音、口语发音和语音质量之间的特定说话者之间的关系，以便对100名说美式英语的人的协同发音语法进行类型化。实验2对这些说话者共同发音元音鼻化的语法规范中的个体差异进行了知觉定义。我们的目标是使用定义跨语言协同发音变异的相同惯例来对跨说话者变异进行类型化，将个人之间的同步协同发音变异与跨语言音系化的语音模式联系起来。预测是，在不同语言之间产生的协同发音模式的不同类型也在不同的说话者之间系统地存在。目的2是研究说话者特定协同发音模式的知觉学习对基于听者的声音变化机制的影响。实验3和实验4考察了对说话者特定协同发音模式的知觉适应，探索了听话者对特定说话者协同发音模式的适应是音系化的一个完整机制。预测是，协同发音的知觉学习是有帮助的，因为它允许听者灵活地预测给定的说话者将如何产生单词。这一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发音的。该项目测试了基于听者的声音变化账户的新扩展，该账户将感知适应与说话者特定的协同发音模式相结合，以解释新的协同发音模式是如何发音的。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.