Down Syndrome Speech Intelligibility Diagnostic Treatment Study

The 'Down syndrome speech intelligibility diagnostic treatment study' is a pilot clinical intervention study assessing the efficacy of an integrative speech treatment approach for individuals with Down syndrome (DS). This study will use a single-subject design with 10 male participants with DS, aged 7 to 16 years. The proposed intervention, combines two treatment approaches that are documented to be efficacious with other speech disorders: 1) The Cycles Phonological Remediation Approach, designed for highly unintelligible speech, as guided by the Hodson Assessment of Phonological Patterns (HAPP-3); and 2) Script training, a functional speech motor intervention that promotes phrase-level productions. During the twelve-week intensive intervention period, both approaches will be adapted to prioritize the production of words with low vowels to incorporate increased practice of the low-front and low-back vowels. This modification is based on the investigator's perceptual, acoustic and anatomic research findings. Outcome measures will include perceptual, intelligibility, and acoustic analyses obtained from acoustic recordings. These measures will be used to assess treatment efficacy, and to gain insight into the motoric versus anatomic limitations in speech production commonly present in individuals with DS.