Grammatical Abilities in Young Cochlear Implant Recipients and Children With Normal Hearing Matched by Vocabulary Size

Abstract

Purpose This study sought to expand understanding of the impact of cochlear implantation on grammatical acquisition by comparing young children who have vocabularies of comparable size. Two research questions were investigated: (a) Do young cochlear implant (CI) recipients have grammatical skills comparable to those of children with normal hearing (NH) matched by spoken vocabulary size? (b) Do these groups show associations between vocabulary size and grammatical measures? Method The participants included 13 CI recipients at 24 months postactivation (chronological ages = 33–60 months; M = 44.62) and 13 children with NH between 27 and 30 months old ( M = 20.69). The 2 groups were matched by their vocabulary size. Four grammatical outcomes were analyzed from the MacArthur Communicative Development Inventory (Fenson, Marchman, Thal, Dale, & Reznick, 2007) and 20-min language samples: (a) grammatical complexity, (b) mean length of utterances, (c) tense marker total, and (d) productivity scores. Results The 2 groups showed comparable grammatical skills across the 4 measures. Consistently significant associations between vocabulary size and grammatical outcomes were found in the CI group, with fewer associations in the NH group. Conclusions The 2 groups showed similar grammatical abilities. The young CI recipients appeared to be following a typical pattern of linguistic development.