Neural Indices of Intervention Outcomes in Children With Speech Sound Disorders

Children with speech sound disorders (SSD) are thought to be unable to detect subtle differences between sounds, though there is little understanding of the underlying perceptual mechanisms implicated in SSD. The investigators suggest that children with SSD may have difficulty creating phonological representations due to inaccurate perception and representation of speech sounds, which then directly impacts speech production abilities. Children will be randomly assigned to one of two treatment conditions in the present study: 1) Traditional speech treatment alone or 2) Traditional speech treatment in conjunction with speech perceptual training. By identifying an underlying mechanism of the disorder, the clinical approach to the treatment of SSD will be better informed and treatment approaches targeting all deficient areas can be utilized.

Five to eight percent of all children in the United States have a speech sound disorder (SSD). Children with SSD have difficulty producing sounds of their target language system. Some of these children also have difficulty perceiving and categorizing speech sounds. It is presently unknown what underlying mechanisms might account for the communication problems children with SSD encounter. One possible explanation is that children with SSD cannot produce speech sounds correctly because they have poorly specified phonological representations, which are the result of inaccurate speech sound perception. Thus, speech sound production errors may stem from imprecise speech perception and its resulting sparse phonological representations. Most children with SSD make slow and steady gains in speech treatment. This is likely due to the fact that speech treatment typically targets just phonetics (i.e., speech production) and phonology (i.e., speech sound knowledge and use). However, it is possible that the underlying mechanisms of speech sound disorders are not specifically phonological in nature but may in fact be related to more general cognitive and/or linguistic impairments. Thus, children will be randomly assigned to one of two treatment conditions in the present study: 1) Traditional speech treatment alone or 2) Traditional speech treatment in conjunction with speech perceptual training. One goal of the research program is to identify what components of treatment induce the greatest amount of phonological change in children with SSD. By comparing the treatment components, the investigators will be able to identify what treatment activities induce the greatest phonological change in children. This information should aid in developing more efficient and effective treatment programs for SSD. A second goal of the research program to use electrophysiological measures (electroencephalogram, EEG; event-related potentials, ERP; frequency following responses, FFR) to examine how phonological representations and their associated auditory neural responses change in conjunction with the two traditional speech treatment approaches. A better understanding of phonological representations and the auditory sensory system in children with SSD will inform how speech evaluations and treatment are best conducted by speech-language pathologists.