Doctoral Dissertation Research: Investigating Sound Change in an Understudied Language: A Sociophonetic Study of Age and Locality Effects

语言变化是生活中的一种现实，在各种语音变化中，元音合并在语言研究中尤为突出。大多数关于元音合并的研究都集中在英语等研究得很好的印欧语言上，解决了与曾经不同的元音的产生和/或感知有关的问题，这些元音正在变得不那么明显(例如，许多说美式英语的人不再区分‘cot’和‘caped’元音，但这些人中的一些人仍然能感觉到这种区别)。然而，在研究较少的非印欧语言中研究元音合并的动态对于理解元音合并是很重要的，因为它们通常包含有研究得很好的语言所没有的元音特征，从而为元音如何随着时间的推移而变化提供了新的见解。这项研究采用混合方法，考察了在一种研究不足的语言中观察到的元音合并的情况，其中包含印欧语言中不存在的元音特征。该项目的发现有助于在一个多语言、研究不足的社会中对语言变异、接触和变化的科学知识，语言变异模式与言语的社会和态度联系之间的关系，以及识别具有独特元音特征的语言中的元音合并的基础。通过收集一系列说话人年龄和地点的语音产生和感知数据，该项目还对语音语言病理学、语言教育学、语音识别技术和法医语言学产生了影响。该项目探索了在以前的元音合并案例中涉及的变异模式，但重点关注一个较罕见的元音合并案例。特别是，该项目考察了人口统计和社会因素，如年龄、性别和地区，是否有助于预测这种情况下合并的程度；元音在发音中的合并是否与感知中的元音合并相对应；以及根据传统元音高度和元音背部维度明显的元音合并是否也在其他较不频繁检查的声学指标中出现一致。该项目通过从两个不同的社区(城市和农村)收集生产和感知数据来解决这些问题，这些社区包括青少年(10-18岁)、年轻人(19-39岁)和老年人(40岁)。产出数据来自对话访谈和图片命名任务；知觉数据来自听力任务。来自制作任务的音频录音经过声学分析，这有助于确定在制作中是否存在元音合并，并支持探索元音合并的其他诊断。研究参与者还完成了一份详细的问卷，其中包括关于语言/方言接触和语言态度的问题。该项目的成果是正在研究的第一个开放获取的语言语料库的基础，是语言研究人员的工具，也是关于正在研究的语言的各种言语规范的信息来源。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。

Language change is a fact of life, and among the various types of sound change, vowel merger has featured particularly prominently in linguistic research. Most research on vowel merger has focused on well-studied Indo-European languages such as English, addressing questions related to the production and/or perception of once-distinct vowels that are becoming less distinct (for example, many speakers of US English no longer produce a distinction between the 'cot' and 'caught' vowels, but some of these speakers can nevertheless perceive the distinction). However, investigating the dynamics of vowel merger in less-studied, and non-Indo-European, languages is important to understanding vowel merger because they often contain vowel features that are absent from well-studied languages and, thus, provide new insights into how vowels can change over time. Using a mixed-methods approach, this project examines a case of vowel merger observed in an under-studied language, which contains a vowel feature absent from Indo-European languages. The findings of the project contribute to scientific knowledge of language variation, contact, and change in a multilingual, understudied society, of the relationship between patterns of language variation and the social and attitudinal associations of speech, and of the basis for identifying vowel mergers in languages with unique vowel features. By collecting speech production and perception data across a range of speaker ages and localities, the project also has implications for speech-language pathology, language pedagogy, speech recognition technologies, and forensic linguistics.This project explores patterns of variation that have been implicated in previous cases of vowel merger but focusing on a rarer case of vowel merger. In particular, the project examines whether demographic and social factors, such as age, gender, and locality, help predict the extent of merger in this case; whether a vowel merger in production corresponds to one in perception; and whether a vowel merger that is apparent according to the traditional vowel height and vowel backness dimensions also appears consistently in other, less frequently examined acoustic measures. The project addresses these questions by collecting production and perception data from two different communities (urban versus rural), including adolescents (ages 10-18 years), younger adults (19-39 years), and older adults (40+ years). Production data come from conversational interviews and a picture-naming task; perception data come from a listening task. Audio recordings from the production tasks undergo acoustic analyses, which help determine whether there is a vowel merger in production and support exploration of additional diagnostics for vowel merger. Study participants also complete a detailed questionnaire that includes questions about language/dialect contact and language attitudes. The project results form the basis of the first open-access corpus of the language being studied, a tool for language researchers and a source of information about various speech norms in an under-studied language.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.