Abstract:
Similar to other human behaviors, speech production is hierarchical. Motor planning is represented in a low-dimensional goal space and unfolds into successively more detailed levels of output. The communicative goal requires a balance between the perception and production systems. If these two systems are appropriately tuned a predictability results that facilitates the communication process. One method that can be used to understand the tuning of these two important processes generally, and the speech production process specifically, is examination of output variability under a variety of conditions. Output variability reflects on the precision of the respective processes and on aspects of the goal-level planning. The purpose of this presentation is to investigate aspects of speech movement planning and control through analysis of lip, jaw, and tongue motion. Two complementary approaches will be used. Static spatial positional goals for a variety of phonetic segments of English will be examined. The continuous motion of simultaneous articulator trajectories will also be examined to elucidate the time-varying nature of speech. The interpretation of both static and dynamic movement variability will be related to the characteristics of the production and perception processes. [Work supported by NIH.]