Throwback Pub (2017): Treating CAS in the under-three crowd

Childhood Apraxia of Speech. Where to begin? If you’ve tried searching for treatment strategies in very young children, like here or here, or read ASHA’s Technical Report (though that one’s now a decade old…), you know it’s slim pickings. There are good treatment strategies for older children. But, ah, hellooo, what do we do before age four?

This study describes the Speech Motor Learning (SML) approach and tested its effect on a 33-month-old boy with CAS. SML is based on the Four Level Framework (FLF) of speech sensorimotor control. The basic idea in the FLF is that there are four phases in processing speech: linguistic-symbolic planning, speech motor planning, speech motor programming, and execution. The motor and sensory systems communicate to develop motor plans and adjust motor programs. See the article for a synopsis of the FLF.

SML uses principles of motor learning to train sound sets of gradually increasing difficulty. The (very basic) idea is to build “core motor plans” for each speech sound, and then build the flexibility to execute those motor plans in varying phonetic contexts. Nonword targets are based on stimulability, accuracy of production, and developmental appropriateness, and are introduced in a series of stages. The SLP trains a small set of stimulable consonants and vowels, and targets CVCV non-words in five levels of increasing difficulty as the child masters each level. For example, the first level might include nonwords like /bɪbu/, /bɪbi/, /bɪba/ and then slowly increase complexity to nonwords like /bɪdu/, /bɪmu/, /bɪgu/.


Does it work? Well, maybe. The boy in this single case study had been involved in an early intervention program using the Hanen program for over a year with minimal improvement in his articulation. He had normal hearing as screened by an audiologist, and scored within normal range on the Rossetti Infant-Toddler Language Scale. Treatment was provided for 9 weeks, and the authors examined whether the treated sounds could be correctly produced in words or nonwords. The child decreased his total number of errors per word and non-word, and improved his production in the first set of targets and some of the second set, but the authors hesitated to attribute all of his progress to the treatment alone because his baseline scores were variable.

For more on the SML approach and FREE software for creating CVCV and CVC stimuli, see the lead author’s website here.


van der Merwe, A., & Steyn, M. (2017). Model-driven treatment of childhood apraxia of speech: Positive effects of the speech motor learning approach. American Journal of Speech-Language Pathology, 1-15.