The Research Framework
What are the origins of child speech disorders?
This figure provides the conceptual framework for ongoing etiologic studies in the Phonology Project. The left arm of the Speech Disorders Classification System, termed SDCS-T, provides a set of descriptive terms (i.e., a typology) for different types of speech sound disorders during the lifespan. The right arm of the SDCS, termed SDCS-E, provides a set of working terms to classify the origins of several subtypes of speech sound disorders (i.e., their etiology). For example, some children's speech delays may be due to genetic factors (SD-GEN), while other speech delays may be due to early recurrent otitis media with effusion (SD-OME), or associated with a motor speech deficit termed apraxia of speech (SD-AOS). Ongoing studies in each of these and other posited subtypes are attempting to determine the origins of child speech sound disorders of currently unknown origin and provide clinicians with the clinical signs that differentiate each subtype.
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What are the most effective ways to help children with speech sound disorders?
This figure illustrates one conceptual framework that the Phonology Project is testing in our treatment studies. A series of retrospective and prospective studies indicates that a child's level of "focus" in treatment is a significant predictor of outcomes. "Capability" is the more important predictor of the two factors, but learning is ultimately influenced by motivational and executive functions that we subsume under the construct of focus. Current studies are investigating what happens after children have learned to produce speech sounds correctly using an etiologically-based approach within the Capability-Focus framework. We are particularly interested in our clinic graduates' reading skills and in their social competence.
