Speech Perception Profiles in Korean-Speaking Children With Speech Sound Disorders.

BACKGROUND: Children with speech sound disorders (SSD) constitute a heterogeneous population, with speech difficulties arising from different loci within the speech processing system. Speech perception has long been implicated in SSD; however, previous findings remain mixed, partly due to differences in task demands and limited consideration of SSD subtypes. In particular, few studies have systematically examined speech perception across multiple contrast types that are explicitly structured around common developmental error patterns and across clinically defined SSD subgroups. AIMS: This study aimed to: (a) compare speech perception performance between children with SSD and typically developing (TD) peers across different phonological contrast types, and (b) examine whether children with articulation disorder, phonological delay, and phonological disorder exhibit distinct perceptual profiles that reflect subtype-specific characteristics. METHODS: Fifty-two Korean-speaking children aged 5-6 years participated (26 SSD; 26 TD). Speech perception was assessed using a minimal-pair identification task incorporating four substitution patterns frequently observed in Korean-speaking children: velar fronting, fricative stopping, affricate stopping, and affrication. Children with SSD were further classified into articulation disorder, phonological delay, and phonological disorder subgroups based on their surface error patterns. Group differences were analyzed in terms of overall accuracy and contrast-specific performance. RESULTS: Children with SSD performed significantly below TD peers on the speech perception task. Across both groups, velar fronting contrasts were the most challenging, whereas contrasts involving manner differences were identified more accurately. Within the SSD group, subgroup comparisons did not reach significance for overall accuracy or for most contrast types; however, a descriptive trend was observed whereby children with articulation disorder showed numerically higher accuracy than children with phonological delay and phonological disorder. A significant subgroup difference emerged specifically for the affricate stopping contrast, with children in the phonological disorder subgroup showing significantly lower accuracy than those in the articulation disorder subgroup. CONCLUSIONS: The findings indicate that speech perception difficulties in SSD are contrast-dependent and preliminary evidence suggests that perceptual vulnerability for certain contrasts (specifically affricate stopping) may differ across SSD subtypes. Rather than reflecting a uniform perceptual deficit, perceptual vulnerability in SSD appears to be most pronounced for contrasts associated with common substitution patterns, with subtype-related differences observed for this specific contrast rather than uniformly across all contrasts tested. WHAT THIS PAPER ADDS: What is already known on this subject Children with speech sound disorders (SSD) often demonstrate poorer speech perception than their typically developing peers, although findings across studies have been inconsistent. Prior research suggests that perceptual weaknesses in SSD may depend on task characteristics and the phonemic contrasts examined, with some evidence pointing to sound-specific difficulties aligned with children's production errors. In addition, SSD is a heterogeneous condition comprising distinct subtypes, such as articulation disorder, phonological delay, and phonological disorder, which differ in surface error patterns and underlying speech processing profiles. However, few studies have examined speech perception across SSD subtypes using contrasts that directly reflect common developmental substitution patterns, particularly in Korean-speaking children. What this study adds to the existing knowledge This study demonstrates that speech perception difficulties in SSD are contrast-dependent rather than uniform and vary meaningfully across SSD subtypes. Using a minimal-pair identification task grounded in developmentally relevant Korean phonological contrasts, the findings show that children with articulation disorder exhibit relatively preserved perceptual sensitivity, whereas children with phonological delay and phonological disorder show reduced performance, with the weakest perception observed in phonological disorder. Importantly, subtype-related differences were evident even at the level of speech perception, extending previous Korean research that has focused primarily on downstream phonological processing measures. These results provide evidence that perceptual vulnerability contributes to the heterogeneity of SSD and aligns with subtype-specific loci of processing difficulty. What are the clinical implications of this study? The findings highlight the value of incorporating speech perception assessment into the evaluation of children with SSD, particularly when differential diagnosis among SSD subtypes is considered. Perceptual assessment may be less critical for children with articulation disorder, whose difficulties appear largely output-based, but should be considered an essential component for children with phonological delay or phonological disorder. In particular, these findings underscore the relevance of speech perception for understanding heterogeneity in SSD, without implying uniform vulnerability across contrast types or children. A subtype-sensitive approach to speech perception assessment and intervention may support more precise clinical decision-making and more effective, individualized treatment planning.