We are interested in causes of speech and language disorders and their impact on life skills. Our research has focused on genetic, neurological and medical basis of speech sound disorders. We have been funded for the last 26 years by the National Institutes on Deafness and Other Communication Disorders, and have followed children with speech sound disorders from preschool through adolescence.

Speech sound disorders are the most prevalent type of communication disorder in early childhood and often place an individual at risk for later academic difficulties. Individuals whose speech sound disorder persists past 8 years of age are at highest risk for poor long-term social-emotional, academic, and vocational outcomes.

Our current project seeks to reveal predictors of long-term problems to which individuals with early speech sound disorders are vulnerable, identify risk factors, and determine deficits to target in early interventions to insure more favorable educational, vocational, and behavioral outcomes.

In our prior studies, we have examined over 275 families of children with early childhood speech sound disorders and followed these children in to school age, adolescence and adulthood. Individuals were tested on a variety of different measures including: articulation skills, phonological awareness, receptive and expressive language, vocabulary, spelling, reading, written language, problem solving skills, narrative skills, oral motor abilities and spontaneous speech and language. Families were also asked to complete a family history and participate in a DNA collection.

Findings from this study demonstrated:

  • Speech and language disorders are familial in nature.
  • There are several subtypes of speech sound disorders: isolated speech sound disorders, speech sound disorders accompanied by language disorders, and apraxia of speech.
  • Children with speech sound disorders alone have better long-term outcomes than children with both speech sound and language problems.
  • Children with speech sound and language problems are more likely to develop reading, spelling and written language disorders in second, third and fourth grades than children with speech sound disorders alone.
  • Candidate genes identified thus far influence brain development.
  • Individuals whose speech sound disorder persists past 8 years of age are more likely to have language, reading, and written language difficulties at adolescence and adulthood.