Phonological development in toddlers with cleft palate and typically developing toddlers aged 12-24 months

Background & Objectives: Toddlers with cleft palate are likely to show different speech-language development from typically developing toddlers starting in the early development stage due to their congenital anomalies of the oral mechanism. Previous studies have reported limited phonological development of young children with cleft palate, but there is no study dealing with phonological development of toddlers with cleft palate based on spontaneous utterance samples in Korea. The present study explores the early phonological development of toddlers with cleft palate through spontaneous utterances considering the characteristics of the Korean consonant system and compares this with the phonological development of typically developing toddlers. Methods: Fourteen toddlers with cleft palate and 14 typically developing toddlers were involved in the research, and the children interacted with the researcher and their primary caregiver in their home. Based on language samples from a 30-minute interaction, the following were analyzed: (1) total number of utterances, (2) types of syllable structure, (3) number of phonetic inventories, (4) frequency and ratio of consonants based on place of articulation, and (5) frequency and ratio of consonants based on manner of articulation. Results: There was no statistically significant difference in total number of utterances, although toddlers with cleft palate tended to use fewer utterances than typically developing toddlers. Toddlers with cleft palate showed significantly lower frequency of CV and CVC types. A statistically significant difference in the number of phonetic inventories was observed. While typically developing toddlers produced approximately 6 to 7 consonants on average, toddlers with cleft palate produced an average of approximately 2 to 3 consonants. Toddlers with cleft palate used significantly less alveolar and palatal sounds and more glottal sounds than typically developing toddlers, which indicated that they prefer the posterior sounds. Toddlers with cleft palate produced significantly less plosive, affricative sounds and more glottal fricatives compared to the toddlers in the control group, which indicated they have difficulty using pressure consonants. Additionally, the toddlers with cleft palate produced less fortis and lax consonants than typically developing toddlers. Discussion & Conclusion: The results of the study indicated that young children with cleft palate tend to prefer simple syllable structure and show limited consonant inventory including only nasal and glottal fricative consonants. The present study investigated the early phonological development of toddlers with cleft palate based on spontaneous utterances considering the characteristics of Korean consonants. Additionally, the study suggests that providing early speech-language evaluation and developing intervention programs which facilitate early phonological development of young children with cleft palate are necessary.