This case study examined the initial and renewed impact of speech generating devices on the expressive communication behaviors of a child with autism spectrum disorder. The study spanned six years of interrupted use of two speech generating devices. The child's communication behaviors were analyzed from video recordings and included communication acts per obligatory context per minute, the percent of total recorded communication acts, the number of different words verbalized synthetically by the SGD and naturally by the child, and the different types of words verbalized synthetically and naturally. Two similar speech generating devices were used in this study. Results indicated that therapeutic use of the speech generating devicess improved the child's ability to expressively communicate by increasing his natural verbalization of words in obligatory context more than therapy utilizing pictures and gestures.