Effect of a Core Vocabulary Intervention Program on Speech Intelligibility in 7-11-year-old Farsi-Speaking Educable Children with Down Syndrome

Speech errors in children with Down Syndrome (DS) are inconsistent, such that in articulating the same lexical item, the children produce it in different ways. The Core Vocabulary Treatment (CVT) has been designed to increase the consistency of articulation in children with inconsistent disorder. The current study was carried out to investigate the efficacy of CVT on the speech intelligibility of 7-11-year-old educable Farsi-speaking DS children.
The study was performed in the form of a pre-posttest design. Four DS children participated in the study. For each case, 12 to 14 treatment sessions were performed. Treatment was accomplished by 70 goal words. The instruments used were Inconsistent subtest of Persian Diagnostic Evaluation of Articulation and Phonology (P-DEAP) and the test of single word intelligibility. There were 7 assessment points in the study: two weeks, one week, and immediately before intervention as well as immediately, one week, two weeks, and six months after the intervention. Subsequently, 10 unfamiliar listeners judged the speech intelligibility in children by recording their speech prior to and after intervention.
The consistency of articulation increased after intervention and generalized to control words. Furthermore, intelligibility of speech also increased after the intervention (P The obtained results, similar to those of other studies, showed that CVT is effective in enhancing the consistency of articulation. Further studies are necessary to ensure confidence in the effectiveness of this intervention to increase the consistency and intelligibility of speech in other languages.