Objective: The purpose of this investigation was to compare the effects of two different specific treatment protocols for acquired apraxia of speech (AOS): Sound Production Treatment (SPT) and Metrical Pacing Therapy (MPT) in four individuals ages 54-80 years old with moderately severe chronic AOS and aphasia following left ischemic stroke. Method: Treatment protocols were compared using a noncurrent multiple baseline across participants and behaviors design. Treatment outcomes were compared with respect to whole word correctness (WWC) in acquisition and generalization of multisyllabic word targets and participant-reported communicative participation. Results: Three of the four participants experienced statistically significant improvements in WWC with SPT, and three of the four participants experienced statistically significant improvements with MPT. Based on a priori analysis measures, three participants demonstrated relatively greater benefit from MPT. Using the measure of communicative participation, three of the four participants reported improvements across the treatment conditions. Only one participant in this investigation indicated a statistically significant change between his communicative participation at baseline and during washout, and this was following the MPT treatment. Conclusion: This investigation demonstrated that individuals in the chronic stages of AOS can benefit from participation in both SPT and MPT, corroborating prior research related to articulatory kinematic and rate and rhythm treatment approaches. Additional investigation is necessary to further identify characteristics of individuals for whom the treatments are most likely beneficial to assist in clinical decision making.
