Sentence Length Effects on Intelligibility in Two Groups of Older Children With Neurodevelopmental Disorders

Area of Science:

• Speech-language pathology
• Developmental disabilities
• Childhood neurodevelopmental disorders

Background:

• Sentence length is a known factor affecting speech intelligibility.
• Its impact on children with neurodevelopmental disabilities, particularly older children, requires further elucidation.

Purpose of the Study:

• To investigate how varying sentence lengths influence speech intelligibility in children with cerebral palsy (CP) and Down syndrome (DS).

Main Methods:

• Nine children with CP and eight with DS (ages 8-17) repeated sentences (2-7 words).
• Three hundred forty adult listeners transcribed the speech to calculate intelligibility scores.

Main Results:

• For children with CP, intelligibility increased with sentence length up to six words, then decreased with seven-word sentences.
• For children with DS, intelligibility increased with sentence length up to six words.
• Sentence length continued to affect intelligibility in adolescents with these neurodevelopmental disorders.

Conclusions:

• Unlike typically developing children, sentence length remains influential for intelligibility in adolescents with neurodevelopmental disorders.
• The relationship between sentence length and intelligibility may differ between CP and DS, potentially influenced by speech motor and cognitive-linguistic factors.