Characteristics of Early Expressive Vocabulary in Mandarin-Speaking Children with Cochlear Implants

Purpose: The aim of this study is to evaluate whether Mandarin-speaking children with cochlear implants (CIs) demonstrated early lexical composition similar to their hearing peers who were at the same vocabulary level and the extent to which children with CIs were sensitive to linguistic and conceptual properties when developing early lexicon. Method: Participants were 77 Mandarin-speaking children with CIs who received CIs before 30 months of age. Their expressive vocabulary was documented using the Infant Checklist of the Early Vocabulary Inventory for Mandarin Chinese 9 or 12 months after CI activation. Percent social words, common nouns, predicates (verbs, adjectives), and closed-class words in total vocabulary were computed for children at different vocabulary levels. Common nouns and verbs were further coded for their word class (noun, verb), word frequency, word length, and imageability to predict how likely a given noun or verb would be produced by children with CIs. Results: Like children with typical hearing, social words were the most dominant category when vocabulary size in children with CIs was smaller than 20 words; common nouns became the most dominant category when the vocabulary size reached 21 words. The difference in percent common nouns and percent predicates (i.e., noun bias) was similar in children with CIs and their hearing peers. In addition, verbs, common words, monosyllabic words, and more imageable words were more likely to be produced by children with CIs than their counterparts. Conclusions: Mandarin children with CIs showed language-specific patterns in early lexical composition like their hearing peers. They were able to use multiple linguistic and conceptual cues when approaching early expressive vocabulary despite perceptual and processing constraints.