The Effect of Mixed Articulation Therapy on Perceptual and Acoustic Features of Compensatory Errors in Children with Cleft Palate.

Background: Compensatory errors are a conventional part of an articulation disorder identified by speech pathologists in patients with Cleft palate (CP). This study aimed to evaluate the effect of new mixed articulation therapy on the perceptual and acoustic features of these errors.

Methods: The single-case experimental design, ABA design, was used in this study. Five CP young children ages 3.9 to 5.4 months, received online multimodal articulation therapy for 5 weeks, 6 sessions per week, utilizing both standard and maximum opposition approaches. Patients underwent baseline and follow-up sessions before and after treatment for 3 weeks-1 session per week. The percentage of compensatory errors was calculated as a perceptual measure, and 2 acoustic measures-including the slope of the locus equation (LE slope) and the overall F2 Transition Frequency Extent (TFE)-were analyzed.

Results: Compensatory errors were eliminated in all 5 participants with the mixed articulation therapy (Percentage of nonoverlapping data [PND] ≥80%, percentage of Improvement Rate Difference [IRD] ≥73.33%), and this therapy effect was maintained for up to 3 weeks of follow-up. The acoustic measures showed a difference in the F2 changes during CV transition in compensatory error before and after therapy.

Conclusion: This study supports the hypothesis that online mixed articulation therapy in children with CP can eliminate compensatory errors. The results of this study can also help extend the knowledge about F2 changes during CV transition in compensatory error before and after speech therapy to create objective and visual diagnostic documentation for patients with CP and prediction of some coarticulation models.