PROJECT SUMMARY Dysarthria is a neuromotor speech disorder that negatively impacts functional communication and social participation for over 50% of children with cerebral palsy (CP). Despite its prevalence among children with CP, little evidence exists to guide treatment of dysarthria in children. Global speech modification strategies (e.g., using a loud voice or slow rate) have shown promise for improving intelligibility in this population; however, children with CP are heterogeneous in their communication skills and motor abilities, and they do not all benefit from these strategies. The effectiveness of speech modification strategies for children with CP is currently limited by a lack of research comparing the efficacy of different strategies and a poor understanding of how these strategies lead to intelligibility gains. The proposed research aims to address this need by comparing the efficacy of three speech modification strategies, and by identifying the “key ingredients” underlying intelligibility gains across different speech modification conditions. Specific Aim 1 will examine the effect of emphatic stress, a novel, local speech modification strategy on intelligibility and speech naturalness for adolescents with CP, compared to two global speech modification strategies (loud speech and slow rate). We hypothesize that the emphatic stress strategy will yield equivalent or greater intelligibility gains and higher naturalness ratings compared to the global loud and slow strategies. Specific Aim 2 will identify quantitative speech measures that best predict within-child changes in intelligibility across speaking conditions. We hypothesize that acoustic and kinematic measures of articulation will better predict within-child intelligibility gains than acoustic measures of task performance. The proposed research will provide information that has the potential to lead to development of a novel, emphatic stress intervention strategy for children with dysarthria. In addition, this research has important implications for improving theoretical understanding of factors that directly contribute to speech intelligibility gains, and could be leveraged to improve individualization of treatment techniques and maximize speech outcomes for children with dysarthria secondary to CP.