A protocol for a randomized-controlled trial to investigate the effect of infant sign training on the speech-language development in young children born with cleft palate.

What is already known on the subject Children with CP ± L are known to be at risk for speech-language delays that impact educational and social emotional growth. Given the limited scientific prove of the impact of early speech-language intervention, no standardized clinical practice guidelines are available yet for children with CP ± L under the age of 3 years. Early intervention in this population mostly focuses on improving verbal input via caregivers or professionals without including a multimodal language input. A growing scientific interest has been seen in the use of infant signs to support speech-language development and caregiver-child interaction in typically developing children and children with developmental delays. What this study adds to existing knowledge No evidence is yet available for the effectiveness and feasibility of early intervention based on infant sign training in combination with verbal input to improve speech-language skills in young children with CP ± L. The current project will investigate the effect of infant sign training on the speech-language development in this population. Outcome measures are compared with those of two control groups: verbal training only and no intervention. It is hypothesized that infant signs may support the intelligibility of verbal utterances produced by children with CP ± L. Improving children's intelligibility may increase the opportunities for these children to engage in early, frequent and high-quality interactions with their caregivers resulting in a richer social and linguistic environment. As a result, infant sign training may result in better speech-language skills compared with the control interventions. What are the potential or actual clinical implications of this work? If providing early intervention based on infant sign training is effective, there is the potential for improved speech-language outcomes in early childhood, resulting in increased speech intelligibility, increased well-being of the child and family and less need for speech-language therapy on the long-term. This project will contribute to the development of evidence-based clinical practice guidelines regarding early speech-language intervention in children with CP ± L under the age of 3 years.