Date of Award


Document Type


Degree Name

Master of Science (MS)


Communication Sciences & Disorders


Down syndrome, or Trisomy 21, is an autosomal dominant chromosomal aberration associated with an extra twenty-first chromosome. Down syndrome causes a variety of physical and cognitive characteristics that make speech and language problems probable Phonology is one such area in which disorders commonly occur for this population As young children acquire the adult sound system, they commonly simplify their productions through the use of phonological processes. Children with Down syndrome use phonological processes for a longer period of time than the typically developing child, often rendering their speech unintelligible.

The purpose of this study was to investigate the clinical efficacy of a visual- gestural cuing system for the remediation of phonological processes in the speech of children with Down syndrome. The speech of the subjects was characterized by at least t wo of the phonological processes for which cues had been developed The cues were designed to represent the following phonological patterns: closed syllables, sequencing consonants, backing, continuancy, liquidity, stridency, and sequencing syllables.

This study was a single subject design replicated across five subjects. An A,, B,, BC, B2, A,, D time-series design was selected and occurred during a period of 34 sessions. The first phase, a baseline phase (A, ), was followed by a cycled intervention phase (B,). During the third phase (BC), the visual-gestural cues were introduced as a supplement to the cycled intervention of phase B, Two extinction phases followed The first, B2, was a cycled intervention phase during which the visual-gestural cues were withdrawn. The second, A2, was the post-treatment baseline phase during which all treatment was withdrawn. A final baseline phase (D) occurred one month later.

The Assessment of Phonological Processes - Revised (APP-R) was presented at the outset of the study to determine the two most prevalent processes and to provide a baseline measure of performance. The APP-R was also administered following the completion of the visual-gestural cuing phase (BC) and following the completion of the study (A2). Further measurements of performance included the collection of probe data, which occurred during each of the six phases. Continuous measurements of performance occurred only during the intervention phases (B,, BC, and B2). A questionnaire, completed by the parent or caregiver at the conclusion of the study, was used as a qualitative measure of performance.

Analysis of the quantitative and qualitative data demonstrated that intelligibility improved significantly with the use of phonological intervention procedures. The visual- gestural cuing system superimposed on the cycled intervention allowed the level of intelligibility to rise beyond that attained with cycled intervention alone. Thus, the visual- gestural cuing system was efficacious in remediating the targeted phonological processes of these subjects. Based on these results, recommendations for further research were proposed.