Document Type




Format of Original

10 p.

Publication Date



American Speech-Language-Hearing Association

Source Publication

Journal of Speech, Language, and Hearing Research

Source ISSN


Original Item ID

doi: 10.1044/jslhr.4301.277


Speech requires the control of complex movements of orofacial structures to produce dynamic variations in the vocal tract transfer function. The nature of the underlying motor control processes has traditionally been investigated by employing measures of articulatory movements, including movement amplitude, velocity, and duration, at selected points in time. An alternative approach, first used in the study of limb motion, is to examine the entire movement trajectory over time. A new approach to speech movement trajectory analysis was introduced in earlier work from this laboratory. In this method, trajectories from multiple movement sequences are time- and amplitude-normalized, and the STI (spatiotemporal index) is computed to capture the degree of convergence of a set of trajectories onto a single, underlying movement template. This research note describes the rationale for this analysis and provides a detailed description of the signal processing involved. Alternative interpolation procedures for time-normalization of kinematic data are also considered.


Published version. Journal of Speech, Language, and Hearing Research, Vol. 43, No. 1 (February 2000): 277-286. DOI. © 2000 American Speech-Language-Hearing Association. Used with permission.

Michael T. Johnson was affiliated with Purdue University at the time of publication.