Word Decoding Skills in Early Elementary Children with and without Speech Sound Disorders and Developmental Dyslexia

Objectives: This study examined word decoding abilities in four groups of early elementary school children: typically developing (TD), those with speech sound disorders (SSD only), those with both SSD and developmental dyslexia (SSD+DD), and those with developmental dyslexia (DD). Methods: Participants were 14 TD children, 4 with SSD only, 10 with SSD+DD, and 13 with DD, all in grades 1 to 3. Word decoding performance was assessed based on two linguistic factors: meaning familiarity (real words vs. nonwords) and phoneme-grapheme correspondence (correspondent vs. non-correspondent). Errors were classified into five types. Results: Significant differences were observed in decoding performance across all groups, with TD children achieving higher decoding accuracy than those in the clinical groups. Across all participants, decoding accuracy was higher for real words compared to nonwords, and for grapheme-phoneme correspondent words compared to non-correspondent ones. Among the five error types analyzed, the most common error in decoding non-correspondent words was the failure to apply expected phonological changes. Conclusion: Both meaning familiarity and grapheme-phoneme correspondence independently influenced decoding performance. Children with co-occurring SSD and DD showed the most pronounced difficulties, suggesting cumulative effects of speech and reading impairments. These findings underscore the need for early identification and intervention in children with overlapping phonological and reading challenges.