Sensorimotor adaptation across the speech production workspace in response to a palatal perturbation

Talkers have been shown to adapt the production of multiple vowel sounds simultaneously in response to altered auditory feedback. The present study extends this work by exploring the adaptation of speech production to a physical alteration of the vocal tract involving a palatal prosthesis that impacts both somatosensory and auditory feedback during the production of a range of consonants and vowels. Acoustic and kinematic measures of the tongue were used to examine the impact of the physical perturbation across the various speech sounds, and to assess learned changes following 20 min of speech practice involving the production of complex, variable sentences. As in prior studies, acoustic analyses showed perturbation and adaptation effects primarily for sounds directly involving interaction with the palate. Analyses of tongue kinematics, however, revealed systematic, robust effects of the perturbation and subsequent motor learning across the full range of speech sounds. The results indicate that speakers are able to reconfigure oral motor patterns during the production of multiple speech sounds spanning the articulatory workspace following a physical alteration of the vocal tract.