Emerging Organization of Consonant–Vowel Combinations in Early Speech Development

Objectives: The emergence of consonant–vowel (CV) combinations in canonical babbling provides a critical foundation for later phonological development. This study aimed to characterize the developmental organization of CV combinations in canonical babbling by examining age-related changes in CV frequency, type diversity, and distribution patterns during the first year of life.Methods: Longitudinal naturalistic speech samples were collected from 14 typically developing Korean infants at two age periods: 6–8 months and 12–14 months. Canonical syllables were identified and transcribed at the syllable level, and CV structures were classified by consonant place of articulation (bilabial, alveolar–palatal, velar) and vowel category (front, central, back). Analyses focused on changes in total CV tokens, the number of distinct CV types, and proportional CV use controlling for individual differences in vocal output. Nonparametric tests were used to examine between-age differences and within-age selectivity of CV combinations.Results: Both the total number of CV tokens and the number of distinct CV types increased from 6–8 months to 12–14 months. Early CV production was concentrated in a small number of frequently repeated CV types, whereas later production showed a more distributed pattern with a wider range of shared CV types across infants. Although no significant between-age differences were found in the proportional use of selected CV combinations, within each age period CV production was not random. Bilabial consonants were more likely to combine with central vowels, alveolar–palatal consonants with front vowels, and velar consonants with back vowels. These selective patterns were more consistently observed at 12–14 months than at 6–8 months.Conclusion: The findings indicate that early CV development in Korean-learning infants involves progressive reorganization from restricted to more diversified CV patterns. Rather than reflecting uniform strengthening of specific CV templates, early CV organization appears to be shaped by relative, developmentally constrained selectivity within the available phonological system.