Intensive Treatment with Ultrasound Visual Feedback for Speech Sound Errors in Childhood Apraxia

Abstract

Ultrasound imaging is an adjunct to traditional speech therapy that has shown to be beneficial in the remediation of speech sound errors. Ultrasound biofeedback can be utilized during therapy to provide clients with additional knowledge about their tongue shapes when attempting to produce sounds that are erroneous. The additional feedback may assist children with childhood apraxia of speech (CAS) in stabilizing motor patterns, thereby facilitating more consistent and accurate productions of sounds and syllables. However, due to its specialized nature, ultrasound visual feedback is a technology that is not widely available to clients. Short-term intensive treatment programs are one option that can be utilized to expand access to ultrasound biofeedback. Schema-based motor learning theory suggests that short-term intensive treatment programs (massed practice) may assist children in acquiring more accurate motor patterns. In this case series, three participants ages 10-14 years diagnosed with CAS attended 16 h of speech therapy over a 2-week period to address residual speech sound errors. Two participants had distortions on rhotic sounds, while the third participant demonstrated lateralization of sibilant sounds. During therapy, cues were provided to assist participants in obtaining a tongue shape that facilitated a correct production of the erred sound. Additional practice without ultrasound was also included. Results suggested that all participants showed signs of acquisition of sounds in error. Generalization and retention results were mixed. One participant showed generalization and retention of sounds that were treated; one showed generalization but limited retention; and the third showed no evidence of generalization or retention. Individual characteristics that may facilitate generalization are discussed. Short-term intensive treatment programs using ultrasound biofeedback may result in the acquisition of more accurate motor patterns and improved articulation of sounds previously in error, with varying levels of generalization and retention.

Keywords: childhood apraxia of speech; intensive treatment program; speech therapy; ultrasound; visual feedback.

Figures

Figure 1

Sample assessment and therapy schedule for a 2-week intensive treatment program. Note: Eight 1-h sessions were provided on each of two treatment targets for a total of 16 h of therapy.

Figure 2

Tongue shapes for distorted and correct productions. Note: Sagittal views of the tongue are shown for /ɹ/ for Alex (top row) and Ben (middle row). Anterior is right and posterior is left. Note the elevation of the anterior tongue on the right side of the correct /ɹ/ productions, and the retraction of the tongue root for correct /ɹ/ relative to incorrect /ɹ/. A coronal view is shown for Craig’s /s/ (bottom row). Note that the correct /s/ has a groove in the middle of the tongue along with elevation of the lateral margins, whereas the distorted /s/ shows the sides of the tongue down.

Figure 3

Performance during acquisition and generalization per participant. Note: The bars represent acquisition (number of trials correct during each session, left vertical axis); the lines represent generalization as assessed by percentage correct on probes for untreated words (right vertical axis). Probe data were obtained prior to treatment (via submitted audio recordings), on the first morning, the fifth morning, and following the final treatment session. Additionally, audio recordings of probes were submitted by Alex and Craig 1–3 weeks after treatment ended to assess retention.