Measuring Speech Intelligibility in Children With Motor Speech Disorders

Purpose Reduced speech intelligibility limits functional communication for many children with motor speech disorders, and improving intelligibility is often a primary goal of intervention. Objective measurement of intelligibility is important for quantifying severity of speech impairment and tracking progress in therapy; however, there is little standardization of methods for measuring speech intelligibility in clinical settings. The purpose of this tutorial is to review different approaches to measuring speech intelligibility in children with motor speech disorders and to discuss the benefits and limitations of using each approach in clinical practice. Method Intelligibility is defined and compared to related constructs. Factors affecting intelligibility of children with motor speech disorders are reviewed. Methods for measuring intelligibility using word identification approaches and scaled ratings are discussed in detail, and their utility in clinical practice is compared. Results Word identification approaches to intelligibility measurement are optimal for tracking progress in therapy but are relatively time consuming. Scaled rating approaches may be adequate in cases where the goal is to obtain an overall measure of severity or for children who are unable to participate in structured testing. Conclusion Different approaches to intelligibility assessment are warranted depending on the clinical goal and characteristics of the child. Speech-language pathologists should consider multiple factors when selecting and interpreting intelligibility measures for their clients.