Variation in children’s vowel production: Effects of language exposure and lexical frequency

According to usage-based models of phonology, the more frequently a word is used and perceived in accented pronunciation variants, the more exemplars of accented tokens are stored and then used for subsequent productions of this word. This may lead to greater production variability in speakers with more variable input than in speakers with less variable input (cf. Pierrehumbert, 2001). This contrasts with abstractionist theories and with proposals according to which children unconsciously filter out accent features. This study assesses the effects of variable input and lexical frequency on speech production by children (mean age 9;10) growing up with one or more languages and with exposure to regional varieties and foreign accents. In a picture-naming task, 60 children were tested on their production of eight German vowels. Children who experience more input variability produced more variable vowels in terms of greater Euclidean distances. Vowels in frequent words were produced with more variability than in infrequent words. Vowel position (F1) differed depending on language background (monolingual versus bilingual) and amount of input in regional varieties. The results imply that greater input variation can account for variable vowel production, in line with usage-based theories.