Research

Overview

We pursue several lines of research in the Speech & Language Lab. In one line of work, we investigate the structure of the speech plan in child and adult language via measurement of speech acoustics and kinematics. In a second line of work, we use individual difference measures to investigate how language and nonlanguage subsystems interact to support the development of hierarchically organized speech. In a third line of work, we investigate the relative weightings of speech factors that contribute to the perception of disorder and the social import of these weightings. Our research is supported in part by the National institute of Child Health and Human Development.

Grant Support

Project Title: Speech Rhythm Acquisition
Source: National Institute of Child Health and Human Development (R01 HD087452), 2017—21.
PI: Melissa A. Redford [w/ Christina Gildersleeve-Neumann (subcontract PI), & Eric Vatikiotis-Bateson* (consultant)]

This project focuses on age-related changes in grammatical word production in children who are typically developing. The working hypothesis is that, once lexical stress is acquired, adult-like English rhythm production depends on grammatical word chunking with adjacent content words. These supralexical chunks are the production units that we hear as prosodic words. We are using long-distance coarticulation to index unit boundaries in children’s speech and to test whether their chunking of grammatical words is based on syntactic affiliation or metrical structure. The influence of specific linguistic and cognitive factors on the development of long-distance coarticulation is also being investigated. The results will inform theory and provide new insights into why speech rhythm is atypical in children with speech planning deficits. The research will also provide important normative data on the extent and strength of long-distance coarticulation in school-aged children’s speech as well as fundamental information about language and speech interactions in typical development. A final aim is to determine which cues most influence the perception of immature chunking patterns, with implications for clinical intervention.

* We are deeply saddened to have lost Eric to cancer in 2017. We miss his abundant generosity, intellectual curiousity, creativity, and yarn-telling.

Project Title: Acquisition of Temporal Patterns in Child Speech and Language
Source: National Institute of Child Health and Human Development (R01 HD061458), 2009—15 (w/ NCE).
PI: Melissa A. Redford [w/ Laura Dilley (subcontract PI), & Doris Payne (co-Investigator)]

This project laid the foundation for modeling the development of skills and strategies that underlie the suprasegmental aspects of speech production. The aim of the project was to characterize a full range of prosodic patterns in 5- to 11-year-old English-speaking children’s speech, with an emphasis on temporal patterns. We sought to identify the rate at which different patterns are acquired in a longitunidal study of children from a relatively understudied age group whose language is functional and complex but prosodically immature. We also sought to identify interactions between timing, intonation, and syntax in children’s speech, and the language and nonlanguage factors that could explain why their prosodic speech patterns are different from those of adults. Our working hypothesis was that children’s rhythmic speech is increasingly modulated over time to highlight conceptual and structural aspects of the message for listeners, which is a major function of adult prosody.