Sign language is an effective form of alternative communication for persons with autism and other developmental disabilities. Only a few studies have systematically measured the effects of sign language on the vocal responses of its users. This study employed a multiple baseline design to evaluate the effects of sign language on the vocal responses of a four-year-old boy with autism. Results indicate that a reinforcement contingency placed only on sign responses is inadequate for maintaining vocal responses. When a reinforcement contingency is placed on sign responses as well as vocal responses that the user is capable of emitting in verbal imitation, both sign and vocal responses are maintained. Results are discussed in terms of the need for a reinforcement contingency placed on vocal and sign responses, the effects of teaching procedures on response variability, and the need for future research to examine procedures utilized to teach sign language to persons within the developmental disabilities population.

Individuals diagnosed with Autism Spectrum Disorder (ASD) have difficulties in forming functional communication. The purpose of this study was to replicate Ishizuka and Yamamoto (2016) to determine which intervention, contingent vocal imitation or contingent vocal responses, produced the highest level of vocalizations of young children diagnosed with ASD in a play-based setting. For the contingent vocal response treatment phase, the experimenter vocally responded to each child vocalization with a response that was topographically different than the child’s response. For the contingent vocal imitation treatment phase, the experimenter vocally imitated the child’s vocalization with a topographically identical response. Two children diagnosed with ASD, ages 41 and 57 months, participated in this study. An alternating treatment design was used to compare the effects of each treatment on increasing child vocalizations. . Results indicated that contingent vocal imitation resulted in a higher number of child vocal imitations for both children. Results also indicated that contingent vocal responses and contingent vocal imitation produced comparable levels of overall vocalizations, which replicated the findings of Ishizuka and Yamamoto (2016). / Applied Behavioral Analysis

Individuals diagnosed with Autism Spectrum Disorder (ASD) have difficulties in forming functional communication. The purpose of this study was to replicate Ishizuka and Yamamoto (2016) to determine which intervention, contingent vocal imitation or contingent vocal responses, produced the highest level of vocalizations of young children diagnosed with ASD in a play-based setting. For the contingent vocal response treatment phase, the experimenter vocally responded to each child vocalization with a response that was topographically different than the child's response. For the contingent vocal imitation treatment phase, the experimenter vocally imitated the child's vocalization with a topographically identical response. Two children diagnosed with ASD, ages 41 and 57 months, participated in this study. An alternating treatment design was used to compare the effects of each treatment on increasing child vocalizations. . Results indicated that contingent vocal imitation resulted in a higher number of child vocal imitations for both children. Results also indicated that contingent vocal responses and contingent vocal imitation produced comparable levels of overall vocalizations, which replicated the findings of Ishizuka and Yamamoto (2016). / Applied Behavioral Analysis