Analysis of Speech Movements: Practical Considerations and Clinical Application

The instrumental evaluation of speech movements is an important adjunct to the assessment and understanding of speech motor disorders. AIl the interface between the nervous system and aerodynamic modifications in the vocal tract, movement variables such as displacement, velocity, acceleration, and their time histories, can provide direct information on speech motor disorders that can only be inferred from acoustic or perceptual evaluation. Impairment in various aspects of neuromotor functioning is reflected in the motion of individual articulators and their coordination, and may reflect early signs of functional change due to disease or trauma. Within certain limits, movement analysis can be used as an objective method for categorizing speech motor disorders and monitoring change due to therapeutic intervention. Further, objective comparison of orofacial motor behavior during speech and nonspeech tasks may provide diagnostic insight into underlying pathophysiological processes. A perspective on the potential utility of speech movement analysis in the assessment, treatment, and understanding of speech motor disorders is the focus of the present chapter. The limitations of speech movement analysis and the need for clinically-relevant research will be presented.