CAREER: Speaker variability and spoken language comprehension

发展科学的核心目标之一是了解儿童如何理解他们高度可变的感官输入。例如，一个孩子怎么知道从上面看的杯子和从侧面看的杯子——两个截然不同的视觉图像——是同一个物体？一个孩子怎么知道她妈妈说的“猫”和她兄弟姐妹说的“猫”——两个发音完全不同的版本——是同一个单词呢？成年人做这些事很容易。然而，孩子们必须弄清楚哪些声音模式是重要的：哪些声音应该与毛茸茸的动物的代表联系起来，哪些应该与说话的人联系起来。此外，由于口语发生得很快，一个词接一个词，孩子必须非常迅速地计算所有这些信息。令人惊讶的是，人们对整理口语中各种声音模式的学习机制知之甚少。一岁的孩子很快学会忽略母语中不存在的声音模式，比如法语鼻音和非鼻音元音之间的区别。然而，目前尚不清楚儿童如何处理与意义没有直接关系的声音模式。这项研究的目的是了解年轻的语言学习者是如何处理与说话者相关的声音变化的——这些声音差异不会改变单词的意思，但会随着说话者的声音、社交和情感特征而变化。该研究探讨了儿童如何应对说话者的变化：它如何影响他们对新词汇的学习；是什么让他们在识别单词时忽略它，但在识别说话人时却集中注意力？他们如何识别声音和声音的特征，如性别和口音；这是如何随着发展而变化的。这项研究有可能改变研究人员对语言习得的看法。这是一个消除声音变化的过程，还是一个积累精细声学知识的过程？更广泛地说，收集到的知识将有助于提高新的声音模式的学习，比如第二语言的单词和不熟悉的口音。通过更全面地探索正常的语言发展，它将有助于了解儿童语言缺陷中缺失或中断的内容。它可能建议改进自动语音识别系统，该系统目前不能很好地处理说话者之间的自然声音变化。最后，这项研究将有助于揭示听众是如何学会根据别人说话的方式来推断别人的。该奖项将支持对科学领域感兴趣的各种学生（研究生，本科生，高中），为未来的科学和技术劳动力做出贡献。它还将使研究者能够与其他研究人员共享实验材料，简化研究过程，加快科学进步的步伐。

One of the core goals in developmental science is to understand how children make sense of their highly variable sensory input. For instance, how does a child know that a cup viewed from the top and a cup viewed from the side--two very different visual images--are the same object? How does a child know that her mother saying "cat" and her sibling saying "cat"--two very different-sounding versions--are the same word? Adults do these things with trivial ease. However, the child has to figure out what sound patterns matter: which sounds should be linked to a representation of furry animals, and which should be linked to the person talking. Moreover, because spoken language happens rapidly, one word after another, the child must compute all of this information very quickly. Surprisingly little is known about the learning mechanisms that sort out the various sound patterns in spoken language. Children in the first year of life rapidly learn to tune out sound patterns that are not present in their native language, such as the difference between French nasalized and non-nasalized vowels. However, it is not known how children process sound patterns that are not directly related to meaning. This goal of this research is to understand how young language learners process talker-related sound variability--sound differences that do not change the meaning of a word, but vary with the vocal, social, and emotional characteristics of the person speaking. The research explores how children deal with talker variability: how it influences their learning of new vocabulary; what allows them to tune it out when recognizing words, but pay attention when recognizing talkers; how well they recognize voices and properties of voices such as gender and accent; and how this changes over development. This research has the potential to transform the way researchers think about language acquisition. Is it a process of tuning out much of the sound variability present, or is it instead a process of accumulating finely-detailed acoustic knowledge? More broadly, the knowledge gleaned will help to improve learning of new sound patterns, such as words in second languages and speech in unfamiliar accents. By more fully exploring normal language development, it will contribute to the picture of what is missing or disrupted in child language deficits. It may suggest improvements to automatic voice recognition systems, which currently do not cope well with the natural acoustic variability among talkers. Finally, the research will help uncover how listeners learn to make inferences about people based on the way they talk. This award will support a variety of students (graduate, undergraduate, high school) interested in scientific fields, contributing to the future science and technology workforce. It will also enable the investigator to share experimental materials with other researchers, streamlining the research process and quickening the pace of scientific advancement.