[Prediction of future language proficiency in Mandarin-speaking cochlear implant recipients based on early childhood vocabulary proficiency].

<b>Objective:</b> The objective of this longitudinal study is to longitudinally monitor the lexical development and language proficiency of Mandarin-speaking children with cochlear implants (CI) over a three-year post-implantation period while also investigating whether early receptive and expressive vocabulary skills can serve as predictors for later language abilities in CI recipients. <b>Methods:</b> In this study, 42 children with CIs were selected as participants, including 19 males and 23 females, and with a mean age at CI activation of 16.6±4.9 months. Receptive and expressive vocabulary skills were assessed using the Infant Checklist of the Early Vocabulary Inventory for Mandarin Chinese (EVI) at one-year post-activation (T1). Additionally, expressive vocabulary sizes were evaluated using the EVI-Toddler Checklist, while syntactic ability was measured by the Grammatical Complexity test of the Mandarin-Chinese Communicative Developmental Inventory for Infants and Toddlers at two years post-activation (T2). The comprehensive language development level of preschool children, including language comprehension, expression, and grammar ability, was examined during the third year post-activation (T3) using the Revised Scale for Assessment of Language Disorders in Preschool Children. Data analysis was conducted using SPSS 22.0. <b>Results:</b> One year after CI activation, children exhibited a mean receptive vocabulary size of 155.7±52.8 and an expressive vocabulary size of 85.1±63.9. T2's expressive vocabulary size was 455.7±167.7, while the Grammatical Complexity score was 36.5±13.0. The original language development score was determined to be 53.6±14.2 at T3. Correlation analysis revealed significant positive associations between T1's receptive and expressive vocabulary with tests conducted at T2 and subsequent language development measured at T3 (<i>P</i><0.01). Furthermore, there was a significant correlation between expressive vocabulary at T1 and both tests conducted at T2 (<i>P</i><0.01), but no significant correlation with subsequent language development measured at T3. Regression analysis showed that T1 receptive vocabulary significantly predicted T2 expressive vocabulary and Grammatical Complexity scores and T3 language development scores. Moreover, the syntactic ability assessed during T2 independently predicted subsequent language proficiency measured at T3. <b>Conclusions:</b> Early receptive vocabulary and grammar ability two years post CI activation significantly predict later language proficiency in children with cochlear implants. Thus, during rehabilitation, emphasis should be placed on enhancing vocabulary and grammar comprehension.