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

元音鼻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，与口头元音相比，口咽发音系统与语音鼻音元音和鼻音元音的声学之间的映射关系却相对较少。这个项目结合了最先进的RT-MRI方法和复杂的建模技术来解决巴西葡萄牙语中元音的共时和历时行为的一些长期存在的问题，对其他许多元音鼻化的语言也有更广泛的影响。本文应用先进的方法收集和分析实时磁共振成像(RT-MRI)，研究巴西葡萄牙语的语音鼻音、语音鼻化元音和口音元音。研究人员争论巴西葡萄牙语中的鼻元音是在音位上截然不同，还是根本上是两个分段(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由鼻音、语音鼻化和口语元音组成的多说话人语料库，为这场辩论增添不同的视角。分析重点放在巴西葡萄牙语元音的口咽差异以及腭咽开口。这项工作旨在说明口音和鼻化元音的潜在口咽形状与语音鼻音的口咽形状不同，表明每个元音都有自己的运动计划。这将增加越来越多的文献，认为鼻音不仅仅是受腭咽开放影响的口头元音，这些元音在口咽方面的差异有助于声音的变化。该项目还将仔细分析巴西葡萄牙语元音的声学，并将扩展到对可以从磁共振图像中提取的声学进行建模。这项研究将对语音历时变化的原因有更深入的了解，特别是关于言语知觉和言语清晰度之间的反馈回路。

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.