Model-driven treatment of childhood apraxia of speech (van der Merwe & Steyn, 2017)

posted on 08.12.2017 by Anita van der Merwe, Mollie Steyn
Purpose: The aim of the study was to propose the speech motor learning approach (Van der Merwe, 2011) as a treatment for childhood apraxia of speech and to determine if it will effect positive change in the ability of a 33-month-old child to produce untreated nonwords and words containing treated age-appropriate consonants (Set 1 sounds), untreated age-appropriate consonants (Set 2), and untreated age-inappropriate consonants (Set 3) and also to determine the nature and number of segmental speech errors before and after treatment.
Method: An A-B design with multiple target measures and follow-up was implemented to assess the effects of treatment of Set 1. Effect sizes for whole-word accuracy were determined, and two criterion lines were generated following the conservative dual criterion method. Speech errors were judged perceptually.
Results: Conservative dual criterion analyses indicated no reliable treatment effect due to rising baseline scores. Effect sizes showed significant improvement in whole-word accuracy of untreated nonwords and real words containing age-appropriate treated sounds and real words containing age-appropriate untreated sounds. The number of errors for all three sound sets declined. Sound distortion was the most frequent error type.
Conclusions: Preliminary evidence suggests potentially positive treatment effects. However, rising baseline scores limit causal inference. Replication with more children of different ages is necessary.

Supplemental Material S1. Overview of a speech motor learning (SML) program for an individual.

Supplemental Material S2. Analysis of the participant's phonetic repertoire.

Supplemental Material S3. Examples of treatment stimuli implemented in the current study.

van der Merwe, A., & Steyn, M. (2018). Model-driven treatment of childhood apraxia of speech: Positive effects of the speech motor learning approach. American Journal of Speech-Language Pathology, 27, 37–51. https://doi.org/10.1044/2017_AJSLP-15-0193


Financial assistance of the National Research Foundation of South Africa toward the master’s studies of Mollie Steyn is acknowledged.