CAREER: Integrating Grammatical and Psycholinguistic Approaches to Phonological Processes in Speech Production

Northwestern University, Evanston IL

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Research in phonology has constructed rich mathematical theories to precisely characterize the systematic patterns of sounds observed in human languages. However, such theories have largely ignored how humans process sounds in real time. For example, when a speaker decides to produce a particular sequence of sounds, how does he plan out the sequence of movements of his lips and tongue to produce the appropriate sounds? These questions have been the focus of research in psycholinguistics, where detailed experimentation has led to sophisticated but largely qualitative theories of human sound processing. This project integrates the strengths of formal linguistic and psycholinguistic approaches to develop a more robust framework for the study of human speech production. The theory, Gradient Harmonic Grammar, builds on the recently-developed Harmonic Grammar, which is a numerical, constraint-based theory of sound structure. The project will extend this theory by incorporating gradience--non-categorical variation in representational and processing mechanisms--which is a central concept in psycholinguistics. Gradient Harmonic Grammar will be tested via a set of quantitative models that examine experimental data from careful, error-free speech and speech containing mispronunciations. The framework and computational tools will then be extended to model the gradient interaction of multiple sound systems in bilingual speakers. To make the Gradient Harmonic Grammar framework maximally accessible to the research community, a set of flexible, user-friendly, open-source applications will be made publicly available over the internet. These applications will include a set of laboratory assignments to help educators bring these tools into the classroom. The experimental work on speech errors can serve as the basis for future research into speech production disorders, for example, those of stroke victims. Additional studies will also use this general framework to help understand how bilingual speakers manage multiple sound systems during speech proudction. Such research is a critical part of understanding human language in an increasingly multilingual, interconnected world.