This dissertation project will advance our understanding of speech sounds in human languages by investigating nasality in languages with rare nasal speech sound systems. Nasal sounds are produced with air flowing through the nasal cavity, such as [m] and [n] in English, and are present in nearly all of the world’s languages. However, much remains unknown about the range of possible nasal speech sounds systems in human languages, and what is responsible for the emergence of different types of nasal systems, meaning that there is a significant gap in our understanding of this fundamental aspect of human language. This study will help fill this gap by: 1) investigating nasality systems in languages that represent two distinct ends of the typological spectrum in terms of the size of the domains over which duration and intensity of nasality are controlled by speakers; and 2) investigating the hypothesis that nasality systems which are very sensitive to the duration and intensity of nasality are associated with languages where nasality plays an important role in making distinctions in meaning. With respect to the typological spectrum of nasality, at one extreme this project will investigate a language that distinguishes speech sounds that differ in the duration of nasality within individual sound segments, as evidenced in contrasts between prenasalized [nt] and postoralized [nt]. At the other extreme, it will investigate a language that exhibits a slow, gradual increase in nasality over entire words, and where nasality is thus less clearly tied to individual sound segments, but rather larger domains encompassing many sound segments. These rare phenomena indicate that speakers of human languages are sensitive to minute distinctions in nasality, both in its temporal extent as well as in the amount of nasal airflow.
That speakers of human languages are sensitive to such fine-grained differences in nasality raises the question of why these phenomena are observed in some languages, but not others. This study investigates the hypothesis that part of the answer lies in the functional load of nasality (a measure of the amount of "work" that any particular contrast does in a language) in different human languages. The functional load of nasality is likely much higher in languages at these extremes of the typological spectrum than it is in other languages for which nasality has commonly been investigated, e.g. English or French, making such languages critical for understanding how the range of nasality systems found in human languages may arise. This project is based on intensive fieldwork with speakers of languages exhibiting different kinds of nasality systems, and relies on two key methodologies. First, interview-style elicitation techniques will allow for a detailed description of the rules that govern the realization of nasality in these languages. Second, the project will develop a corpus of oral narratives in these languages, which will be transcribed, translated, and archived for the preservation and dissemination of these data. An analysis of the corpora will make it possible to measure the functional load of nasality in these languages and shed light on how functional load is related to the types of speech sounds found in human languages.
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.
