| Traditional theoretical approaches to the study of child language tend to isolate individual areas of language knowledge and often ignore important interactions between different areas of development. Interactions between the development of the linguistic sound system (phonological development) and vocabulary growth (lexical development) have been identified and are now being considered more seriously in theories of language acquisition. A relatively new approach to phonology, Usage-based phonology, offers a promising alternative to more traditional approaches in its ability to incorporate observed patterns of child speech and in its ability to account for the bidirectional nature of the relationship between phonology and the lexicon. One aspect of phonological development that has often been ignored is the phenomenon of variation in production; both inter- and intraword variability have been identified as common processes in early language acquisition. The current study investigates the possible role of a variety of aspects of language use on young, typically developing children's production of known, monosyllabic, real words. The lexical characteristics of word frequency, phonological neighborhood density, and age-of-acquisition were investigated in relation to accuracy and variability of production in two different age-groups: 24 month-olds and 29 month-olds. A variety of predictions stemming from the Usage-based constructs of type and token frequency were made. Results indicate that these lexical characteristics do influence young children's production of known words. Specifically, phonological neighborhood density was found to facilitate production (high density words were more accurate and less variable than low density words), a moderate effect of word frequency on variability was observed (high frequency words tended to be less variable), and age-of-acquisition was found to affect accuracy of production (later acquired words were more accurate than early acquired words). Word frequency and phonological neighborhood density were calculated using both adult and child-based measures; both measures were used in the analyses and differences and similarities are discussed. Results provide additional, previously uninvestigated information regarding typical phonological development and may prove useful for the planning, implementation, and monitoring of progress during intervention for children with disordered phonological development. |
