CAREER: Speaker variability and spoken language comprehension

发展科学的核心目标之一是理解儿童如何理解他们高度可变的感觉输入。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的母亲说的“猫”和她的兄弟姐妹说的“猫”--两个听起来非常不同的版本--是同一个词呢？成年人可以轻而易举地做这些事情。然而，孩子们必须弄清楚什么声音模式很重要：哪些声音应该与毛茸茸的动物的表现联系在一起，哪些声音应该与说话的人联系起来。此外，由于口语发生的速度很快，一个词接着一个词，孩子必须非常快地计算出所有这些信息。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。一岁大的孩子很快就会学会忽略母语中不存在的发音模式，例如法语鼻化元音和非鼻化元音之间的差异。然而，目前还不知道儿童如何处理与意义没有直接关系的声音模式。这项研究的目标是了解年轻的语言学习者如何处理与说话者相关的声音可变性--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。这项研究探索了儿童如何应对说话者的可变性：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了这一点，但在识别说话者时要注意；他们对声音和声音特性(如性别和口音)的识别能力如何；以及这种变化如何影响发展。这项研究有可能改变研究人员对语言习得的思考方式。这是一个调谐掉存在的大部分声音可变性的过程，还是相反，它是一个积累精细详细的声学知识的过程？更广泛地说，所收集的知识将有助于改善对新发音模式的学习，例如第二语言中的单词和不熟悉口音的语音。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缺失或中断的情况。它可能会建议对自动语音识别系统进行改进，目前该系统不能很好地应对说话者的自然声学变化。最后，这项研究将有助于揭示听众是如何学会根据说话方式对人进行推断的。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、高中生)，为未来的科学技术劳动力做出贡献。它还将使研究人员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.