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

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

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