Trajectories of receptive and expressive vocabulary in Mandarin speaking children under 4 years of age fitted with cochlear implants: a 12-month longitudinal study

Objective: To explore trajectories of receptive and expressive vocabulary in Mandarin-speaking children under the age of 4 years, fitted with cochlear implants (CIs). Design: Vocabulary trajectories were measured at baseline, 3, 6, and 12 months after implantation using the Chinese version of the MacArthur-Bates Communicative Development Inventory. Study sample: There were 216 children with CIs in West China Hospital who took part and were divided into three groups based on age at first CI. Results: Receptive and expressive vocabulary scores of the younger implantation group were significantly different from the older groups at baseline. After 12 months of implant use, there were no significant differences between all groups. Furthermore receptive vocabulary trajectories for all children with CIs were not significantly different from those of children with normal hearing. However, expressive vocabulary trajectories were poorer when compared to children with normal hearing. Significant differences were seen between receptive and expressive vocabulary in all age groups. Conclusions: This study suggests no differences in vocabulary trajectories in Mandarin-speaking children whether they received their first CI at 1, 2, or 3 years of age. It is important that clinicians convey realistic expectations about potential differences in receptive vs. expressive trajectories for Mandarin-speaking children fitted with CIs.