Early prelingual auditory development and speech perception at 1-year follow-up in Mandarin-speaking children after cochlear implantation

Objective: The primary purpose of the current study was to evaluate early prelingual auditory development (EPLAD) and early speech perception longitudinally over the first year after cochlear implantation in Mandarin-speaking pediatric cochlear implant (CI) recipients. Outcome measures were designed to allow comparisons of outcomes with those of English-speaking pediatric CI recipients reported in previous research. Method: A hierarchical outcome assessment battery designed to measure EPLAD and early speech perception was used to evaluate 39 pediatric CI recipients implanted between the ages of 1 and 6 years at baseline and 3, 6. and 12 months after implantation. The battery consists of the Mandarin Infant-Toddler Meaningful Auditory Integration Scale (ITMAIS), the Mandarin Early Speech Perception (MESP) test, and the Mandarin Pediatric Speech Intelligibility (MPSI) test. The effects of age at implantation, duration of pre-implant hearing aid use, and Mandarin dialect exposure on performance were evaluated. EPLAD results were compared with the normal developmental trajectory and with results for English-speaking pediatric CI recipients. MESP and MPSI measures of early speech perception were compared with results for English-speaking recipients obtained with comparable measures. Results: EPLAD, as measured with the ITMAIS/MAIS, was comparable in Mandarin- and English-speaking pediatric CI recipients. Both groups exceeded the normal developmental trajectory when hearing age in CI recipients and chronological age in normal were equated. Evidence of significant EPLAD during pre-implant hearing aid use was observed; although at a more gradual rate than after implantation. Early development of speech perception, as measures with the MESP and MPSI tests, was also comparable for Mandarin- and English-speaking CI recipients throughout the first 12 months after implantation. Both Mandarin dialect exposure and the duration of pre-implant hearing aid use significantly affected measures of early speech perception during this time period. Conclusions: EPLAD and early speech perception exhibited similar patterns of improvement during the first 12 months after early cochlear implantation. The duration of pre-implant hearing aid use had a significant positive effect on both categories of outcome measures. Consistent post-implant EPLAD trajectories and early speech perception results provide objective evidence that can guide best practices in early intervention protocols. (C) 2011 Elsevier Ireland Ltd. All rights reserved.