Doctoral Dissertation Research: Effects of phonological contrast on phonetic variation

每当有人说话时，他们都会产生复杂的声波。了解这些声波的声学细节可以帮助改进语音识别技术，并提供对语言差异的洞察力，这可能有助于语言学习。语言学和相关学科的大量研究表明，说话者并不总是以同样的方式发音。例如，英语中的"p"在不同的语境（单词的开头和单词的结尾）和不同的时间会有不同的发音，因为说话的人是人类。人们通常听不到这些差异，但它们存在于声学中，并且可以测量。言语的变异是很自然的，在每一种语言中都会发生。然而，人们对不同语言中究竟有多少变化知之甚少。这项研究试图通过调查某些语言的使用者是否比其他语言的使用者有更多的发音变化来弥补这一差距，以及如何解释这种差异。一个常见的假设是，拥有更多声音的语言的使用者在发音时会表现出更少的变化（更精确）。研究人员将从不同的语言中收集数据来测试和修正这一假设。他们还将制定具体的方法来测量语言中的声学变化，然后可以应用于未来的工作。实验比较了印地语（"B"，"bh"，"p"和"ph"）和英语（"B"和"p"）中的停止音，以及波兰语（"s"，"#347;"和"sz"）和法语（"s"和"sh"）中的咝咝声。&两个实验都考察了每种语言中对比的多种声学线索。该项目的第二部分将使用这些实验的结论来调查说话者是否模仿他们听到的其他说话者的变化。说话者根据他们最近听到的语音改变他们的发音是有据可查的，但是不知道说话者是否会根据他们听到的内容改变他们语音中的可变性的量。为了解决这个问题，研究人员将进行一项模仿研究，让说话者在被提示说话之前先听一听，看看他们的语音变化是否会在听完之后发生变化。这些研究的结果将增加对不同语言和语境中发音差异的理解。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Every time someone speaks, they produce complex sound waves. Understanding the acoustic details of these sound waves can help improve voice recognition technologies and provide insight on language differences which can potentially aid in language learning. A large body of work in linguistics and related disciplines has shown that speakers do not always pronounce sounds in the same way. For example, the sound "p" in English will be pronounced differently in different contexts (beginning of a word vs. end of word) and at different times simply because talkers are humans. People do not usually hear these differences, but they are present in the acoustics and can be measured. Variation in speech is natural and happens in every language. However, less is known about exactly how much variation occurs in different languages. This research seeks to address this gap by investigating whether speakers of some languages have more variable pronunciation than speakers of other languages and what might explain the difference.One frequently assumed hypothesis says that speakers of languages with more sounds will show less variation (be more precise) when they pronounce those sounds. The researchers will gather data from different languages to test and revise this hypothesis. They will also develop concrete methods for measuring acoustic variability in language which can then be applied to future work. The experiments compare stop sounds in Hindi ("b", "bh", "p" and "ph") and English ("b" and "p"), and sibilant sounds in Polish ("s", "ś", and "sz") and French ("s" and "sh"). Both experiments examine multiple acoustic cues to the contrasts in each language. The second portion of the project will use the conclusions from these experiments to investigate whether speakers imitate the variability of other speakers that they hear. It is well documented that speakers change their pronunciation based on speech they have recently heard, but it is not known whether speakers will change the amount of variability in their speech based on what they have heard. To address this question, the researchers will carry out an imitation study where speakers listen to speech before being prompted to speak to see if the variability in their speech changes after listening. The results of these studies will increase understanding of variability in pronunciation across different languages and contexts.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.