This research has been supported by Hallym University Research Fund (No. HRF-201903-010). Objectives: Accuracy of phonemes can vary in terms of phonetic and linguistic contexts of test words. This study aims to examine percentage of consonants correct (PCC) and age of acquisition of consonants in Korean-speaking children in one-syllable word contexts. Methods: This study included 251 Korean-speaking children aged 2;6 through 5;11 who produced 18 one-syllable words. PCC and PCC-Revised were calculated from 18 initial consonants and 7 final consonants. Two-way ANOVAs were performed whether PCC and PCC-Revised were significantly different according to gender and age. Ages of acquisition across all the initials and finals were determined if 50%, 75%, and 90% of children at a specific age produced correctly. Results: PCC and PCC-Revised showed significant differences across age groups. The mean PCC for the children at age 2;6 was approximately 80%-85%; and by 4;0-4;11, it climbed to approximately 90%. PCC for children aged 5;0 to 5;11 exhibited approximately 98%. Seventy-five percent or more of the children correctly produced most plosives, nasals, /h/, /tɕ/, and final /l/ earlier than age 2;6. Final /k/ reached the criterion by 3;5 and /tɕ*/, /tɕ h / reached the criterion by 4;5. Initial /l/, /s/ and /s*/ reached the criterion by 5;5. Conclusion: This study presented PCC and ages of acquisition of consonants in Koreanspeaking children in one-syllable word contexts. This study suggested that children's sound productions should be assessed and interpreted considering phonetic contexts and linguistic units of test materials.

The purpose of this study was to compare the phonological processing abilities (PPA) between children with speech sound disorder (SSD) and typically developing children (TD) in early elementary school years, and to examine phonological processing abilities according to subtypes of SSD. Methods: The participants were 32 children with SSD and 21 typically developing children in the first to the third grades. Children with SSD were divided into children with articulation disorders, phonological delays, and phonological disorders. The tasks for PPA consisted of (1) phonological awareness (PA) tests at syllable and phoneme levels, (2) phonological memory (PM) tests including non-word repetition (NWR), digit forward recall (DF), and digit backward recall (DB), and (3) rapid automatized naming (RAN) tests conducted by numbers and letters. Results: Children with SSD and TD showed significant differences in NWR. As a result of examining the PPA among subgroups of SSD, children with phonological disorders showed significantly lower performance in the NWR and the RAN than children with articulation disorders. Also, children with phonological delays and phonological disorders showed significantly lower performance in the DB task than children with articulation disorders. Conclusion: Significant differences were found between children with SSD and TD in NWR task among the PPA tasks, suggesting the clinical usefulness of the NWR task. This study suggests that children with SSD form a heterogeneous group who differ in terms of involvement of other aspects of speech processing model.

Objectives:The purpose of this study is to examine the distribution tendency when classifying subgroups of children with speech sound disorders according to linguistic symptomatology, which are divided into subtypes of speech sound disorders based on the error patterns and inconsistency. Methods: Based on the error patterns and consistency of speech production, 133 children aged 3-9 years were divided into 4 groups; articulation disorder, phonological delay, consistent phonological disorder, and inconsistent phonological disorder. In addition, we examined the differences in age, percentage of consonants correct, and vocabulary by subgroups of speech sound disorders. Results: The results showed that of 133 children, 30.08% had an articulation disorder, 44.36% had a phonological delay, 18.05% had a consistent phonological disorder, and 7.52% had an inconsistent phonological disorder. There was a significant difference in age distribution according to subgroups of speech sound disorders, and age of children with articulation disorder was significantly higher than other groups. Speech severity was significantly higher in children with consistent and inconsistent phonological disorders than in children with articulation disorders and phonological delays. Receptive and expressive vocabulary did not differ between subgroups of speech sound disorders. Conclusion: This study examined linguistic symptomatology for differential diagnosis. This will be the basis for accurate differential diagnosis of children with speech sound disorders and provide effective interventions for each subgroups.

This study aims to investigate frequency of consonants and the phonemic characteristics of the initial position of eojeols in spontaneous speech samples from typically developing children age 18 to 30 months. Methods: Twenty children age 18 to 24 months and 20 children age 25 to 30 months participated in the study. Spontaneous speech samples were collected while children interacted with their parents and an examiner and were phonetically transcribed. The speech samples consisted of 5,622 utterances and 11,258 eojeols, from which consonants frequencies, frequency ratios by consonants types, consonant types of the initial position of eojeols, and articulation accuracy of the initial consonants were obtained. Results: /k, n, m, t, ŋ/ showed the highest frequency rates. Alveolar sounds by articulation places and plosive sounds by manners showed the highest frequency rates. The 18-to 24-month-old children showed a significantly higher rate of plosive sounds and lower rate of liquid sounds than the 25-to 30-month-old children. The frequency rates of obstruents and sonorants were 61.65% and 38.35%, respectively, for both age groups. The rates of eojeols beginning with obstruents and sonorants were 44.59% and 55.41%, respectively, in both age groups. The percentage of consonants correct in the initial consonants of eojeols was significantly higher in the 25-to 30-month-old children (88.46%) than 18-to 24-month-old children (77.65%). Conclusion: This study has implications for choosing target phonemes of speech therapy and in assessing whether children select or avoid words based on the limitations of their phonological development.

Objectives: Sentence repetition tasks (SRTs) are clinically useful tasks for examining working memory ability and discriminating residual language delay. This study aims to examine sentence repetition skills by groups of children with SSDs and analyze error types and morphosyntactic strengths and weaknesses in SRTs. Methods: Thirty-four children aged 5-7 years with SSDs were classified into groups with articulation disorders, phonological delays, and phonological disorders. SRTs were conducted, and errors in SRTs were analyzed in terms of lexical and grammatical morphemes and children’s sentence repetition (SR) skills were examined by two scoring systems including or excluding articulation errors. Results: In SRTs, children with phonological disorders showed more omission errors; in particular, omission of grammatical morphemes, and sentence paraphrase errors were more frequent. Children with phonological disorders showed more lexical grammatical morpheme errors than the other subgroups. Even in the scoring system that reflects both language and articulation errors, children with phonological disorders showed a lower performance than children with articulation disorders. Conclusion: Children with phonological disorders exhibited morphosyntactic weakness by showing greater difficulties in repeating grammatical morphemes accurately in SRTs. This finding suggests that systematic grammar intervention should be addressed for children with phonological disorders.