Central auditory processing and interhemispheric integration: the relationship between speech sound coding disorder and articulation disorder

This study aims to demonstrate that speech sound disorders associated with central auditory processing disorder stem from a processing disorder in the central auditory pathways during listening, rather than from an articulation-based disorder. Included 25 children with articulation problems (WAP; 7 females, 18 males) and 25 typically developing children without articulation problems (WoAP; 10 females, 15 males), aged 5-8 years. Assessments comprised the Hacettepe Articulation Test, Scan-C subtests (Filtered Words, Auditory Figure-Ground, Competing Words, Competing Sentences), and the Denver II Developmental Screening Test. The Children in the WAP group scored low on the left ear only in the dichotic words and dichotic sentences tests. Left ear performance was significantly lower in the dichotic words test (p = 0.026, Cohen's d = 0.609) and the dichotic sentences (p = 0.001, r = 0.427). These results suggest that articulation disorders may indicate a central auditory processing deficit, particularly a delay in right-hemisphere auditory maturation. It has been observed that in children with central auditory processing disorder, whatever speech sounds they process defectively during listening, they also produce those same sounds defectively. In this context, this study offers a new perspective on the relationship between articulation disorders and central auditory processing. Therefore, it is recommended that central auditory processing screening be conducted in children with articulation disorders to distinguish the underlying disorder.