Acoustic and kinematic characteristics of vowel production through a virtual vocal tract in dysarthria

Broadening our understanding of the components and processes of speech sensorimotor learning is crucial to furthering methods of speech neurorehabilitation. Recent research in limb sensorimotor control has used virtual environments to study learning in novel sensorimotor working spaces. Comparable experimental paradigms have yet to be undertaken to study speech learning. We present acoustic and kinematic data obtained from participants producing vowels in unfamiliar articulatory-acoustic working spaces using a virtual vocal tract. Talkers with dysarthria and healthy controls were asked to produce vowels using an electromagnetic articulograph-driven speech synthesizer for participantcontrolled auditory feedback. The aim of the work was to characterize performance within and between groups to generate hypotheses regarding experimental manipulations that may bolster our understanding of speech sensorimotor learning. Results indicate that dysarthric talkers displayed relatively reduced acoustic working spaces and somewhat more variable acoustic targets compared to controls. Kinematic measures of articulatory dynamics, particularly peak speed and movement jerk-cost, were idiosyncratic and did not dissociate talker groups. These findings suggest that individuals with dysarthria and healthy talkers may use idiosyncratic movement strategies in learning to control a virtual vocal tract, but that dysarthric talkers may nonetheless exhibit acoustic limitations that parallel deficits in speech intelligibility.