He was trained as a clinical linguist at the University of Groningen (The Netherlands) and received his Ph.D. in Language and Communicative Disorders from San Diego State University & the University of California, San Diego. His research focuses on speech production in children and adults with and without speech disorders, and combines a theoretical component and a clinically-oriented component, including treatment research. His research has been funded by the National Institutes of Health (NIDCD), the American Speech-Language-Hearing Foundation, and the Childhood Apraxia of Speech Association of North America.