The "Sound of Silence": Sensitivity to Silent Letters in Children With and Without Developmental Language Disorder.

Purpose Children with developmental language disorder (DLD) demonstrate general spelling difficulties. This study investigated accuracy on and sensitivity to silent letters in spelling in children with and without DLD. Investigating silent-letter production provides a window into orthographic and morphological knowledge and enhances understanding of children's spelling skills. Method A group of children with DLD (M age = 9;11 [years;months]) and two control groups of typically developing children (n = 30 in each group) were given a dictated spelling task of 44 words that each contained a derivational or a nonderivational silent letter. We coded the silent letter in each word and counted 1 point for each correctly spelled letter in order to examine accuracy on silent letters. Two error patterns were distinguished to analyze sensitivity to silent letters: silent-letter substitutions and silent-letter omissions. Results Repeated-measures ANOVA showed that children with DLD produced significantly more errors on silent letters than did both control groups. Both control groups showed a greater sensitivity to silent-letter endings, as they tended to substitute incorrect silent letters where they made errors. In contrast, children with DLD tended to omit silent letters in their spelling attempts. Conclusions Our results suggest that silent-letter production is a major source of difficulty for spellers, especially for those with DLD, who appear to lack sensitivity to silent letters. These results highlight the importance of promoting spelling instruction to enhance orthographic knowledge in children with DLD.