Thesis Title

A Comparison of Speech Output Types For a Child With a Developmental Disability


Lisa McNamara

Date of Graduation

Spring 2006


Master of Science in Communication Sciences and Disorders


Communication Sciences and Disorders

Committee Chair

Lisa Wood


The purpose of the current study was to analyze the effects the type of speech output has on the communication of an individual with a developmental disability. Current research has shown positive impacts on the language abilities of children using speech generating devices (SGDs). However, little research has addressed the influence of the type of speech output from SGDs on language. Baseline treatment sessions used a static communication board. Treatment sessions alternated use of a SGD with synthesized speech output with a digitized speech output. Naturalistic pausing, prompting, and modeling of two-symbol utterances were provided during three different play activities. The follow dependent variables were coded: AAC mode use, spontaneous on-task verbalizations, one-symbol utterances, and multi-symbol utterances. Results revealed a similar percentage of verbalizations produced with the communication board and digitized speech output. Synthesized speech output resulted in a much lower percentage of verbalizations in comparison. Production of multi-symbol utterances increased while production of one-symbol utterances decreased over time. Furthermore, the highest percentage of production of multi-symbol utterances occurred during the synthesized speech output condition. Finally, the SGD with synthesized speech output resulted in the highest percentage of use.


Augmentative and Alternative Communication (AAC), Speech Generating Devices (SGD), digitized speech output, synthesized speech output, natural speech, multi-symbol utterances

Subject Categories

Communication Sciences and Disorders


© Lisa McNamara