Speech Sound Disorders

This study is a single-blind, randomized controlled trial evaluating the efficacy of ultrasound visual biofeedback (UVB) in the treatment of Childhood Apraxia of Speech (CAS) among Brazilian children. Approximately half of the participants are randomly assigned to an Experimental group receiving the ultrasound biofeedback intervention, and the other half to a Control group receiving conventional motor-based therapy without ultrasound. Randomization is performed using a computer-generated sequence (allocation ratio 1:1), with allocation concealment (e.g. sealed opaque envelopes) to prevent selection bias. Blinding is maintained for outcome assessment: an independent speech-language pathologist who is masked to group assignment will evaluate pre- and post-therapy speech samples for all children. Neither the therapists nor the participants are blinded (due to the nature of the intervention), but the use of blinded outcome evaluators helps ensure objective assessment.