Research in this laboratory is concerned with the development of phonological abilities in children developing language typically, and with what goes wrong in this process for children at risk for language problems, including deaf children. The primary interest focuses on how children learn to recover phonemic structure from a complex acoustic signal that lacks invariant information about those phonemes. Another area of interest concerns how the development of phonemic knowledge is affected by conditions that put children at risk for language problems. This work is significant because learning to recognize phonemic structure in the acoustic speech signal is a necessary precursor to many other kinds of language skills, such as reading.
Because children with even mild hearing loss or children growing up in poverty seem to have some language delay, it may be that a child's ability to discover the phonemic structure of language is dependent on language experience. However, many children with reading disorders have had sufficient amounts of the right kinds of early language experience, but nonetheless have difficulties with language. Thus, other perceptual deficits are the likely source of problem for these children. A long-term goal for this laboratory is to investigate what goes wrong in the development of phonemic knowledge in children who encounter difficulty learning language.
This project is funded through a grant from the National Institutes of Health-National Institute on Deafness and Other Communication Disorders. It seeks to examine how normally developing children learn to recover phonemic structure from the ongoing speech signal, which lacks any explicit segmental structure, as well as how they learn to produce speech in the precisely organized fashion of adult speech. The first finding to come out of this work showed that attentional (or weighting) strategies influence the recovery of phonemic structure. More recently, we have been interested in how children discover appropriate strategies of perceptual organization for speech signals.
Along with typical development, work in the Speech Development Laboratory has examined the perceptual underpinnings of language-learning problems. The principal motivation for this work is to improve our understanding of the language-learning problems faced by children with hearing loss. However, studies with other populations of children extend our understanding of the effects of hearing loss on language learning and, at the same time, provide insights into the problems faced by those populations. A population of special interest is children with reading disorders.