Doctoral Dissertation Research: Articulatory and acoustic patterns in phonemic and phonetic nasalization

元音鼻音化是世界语言中许多重要的、被广泛证实的历时和共时语音过程的核心。然而，相对而言，人们对口咽发音系统与语音上的鼻元音和语音上的鼻化元音的声学关系知之甚少。该项目结合了最先进的rt-MRI方法和复杂的建模技术，解决了巴西葡萄牙语中元音共时性和历时性行为的一些持久问题，对许多其他元音化语言具有更广泛的影响。本论文采用先进的方法收集和分析实时磁共振成像（rt-MRI）来研究巴西葡萄牙语的语音鼻音，语音鼻音化，andoral元音。研究人员争论巴西语和葡萄牙语的鼻元音是否在语音上是不同的，或者实际上是两个音段（一个口头元音后面跟着一个鼻辅音）。这项工作将通过构建和分析一个多说话人的鼻音、语音化元音和口语元音语料库，为这场辩论增加一个不同的视角。分析的重点是巴西葡萄牙语元音的口咽差异，以及腭咽开口。这项工作的目的是表明潜在的口咽形状的口头元音和鼻化元音不同于那些音位鼻元音，这表明每个元音有自己的运动计划。越来越多的文献认为鼻音元音不仅仅是受腭咽开口影响的口头元音，而且这些元音的口咽差异有助于声音的变化。该项目还将包括对巴西葡萄牙语元音的声学分析，并将扩展到可以从磁共振图像中提取的声学建模。本研究将进一步深入了解历时性声音变化的原因，特别是关于语音感知和语音发音之间的反馈循环。

Vowel nasalization lies at the heart of a number of important, widely-attested diachronic andsynchronic phonological processes throughout the world's languages. However, relatively littleis understood about the mapping between the oro-pharyngeal articulatory system and theacoustics of phonemically nasal and phonetically nasalized vowels compared to their oralcounterparts. This project combines state-of-the-art rt-MRI methods and sophisticated modelingtechniques to solve some persistent problems regarding the synchronic and diachronic behaviorof vowels in Brazilian Portuguese, with wider implications for many other languages with vowelnasalization.This dissertation applies advanced methodologies in the collection and analysis of real-timemagnetic resonance imaging (rt-MRI) to study phonemically nasal, phonetically nasalized, andoral vowels in Brazilian Portuguese. Researchers debate whether nasal vowels in BrazilianPortuguese are phonemically distinct or are underlyingly two segments (an oral vowel followedby a nasal consonant). This work will add a different perspective to this debate by constructingand analyzing a multi-speaker corpus of nasal, phonetically nasalized, and oral vowels.Analysis focuses on oro-pharyngeal differences in Brazilian Portuguese vowels, as well asvelopharyngeal opening. This work aims to show that underlying oro-pharyngeal shape of oralvowels and nasalized vowels differs from those of phonemic nasal vowels, suggesting that eachvowel has its own motor plan. This will add to a growing body of literature arguing that nasalvowels are not merely oral vowels affected by velopharyngeal opening, and that oro-pharyngealdifferences in these vowels contribute to sound change. The project will also involve carefulanalysis of the acoustics of Brazilian Portuguese vowels and will extend to modeling theacoustics that can be drawn from MR images. This study will give more insight into the causesof diachronic sound change, specifically with regard to the feedback loop between speechperception and speech articulation.