Application of communication development inventories in the examination of early bimodal bilingualism

Hearing children of deaf adults (CODAs) are bimodal bilinguals who acquire sign language at home and spoken language through hearing contacts. This study presents the first systematic description of the bimodal competence of CODAs in Spain using comparable instruments to evaluate language acquisition. A total of 26 signing-hearing children (aged 8-31 months) with at least one deaf signing parent were assessed every four months (82 CDIs per language) using the Spanish Communication Development Inventory and the Spanish Sign Language adaptation. A repeated measures analysis of variance showed no main effect of language, and a significant effect of age. There was a notable increase in vocabulary from 20 to 23 months in both languages.