Effect of different cochlear implantation timings on long-term language development outcomes of pediatric unilateral cochlear implant cases.

INTRODUCTION

Cochlear implantation provides an opportunity for children with congenital severe to profound hearing loss to acquire spoken language. However, as multiple factors influence language outcomes after cochlear implantation, language development performance can vary between individuals.

MATERIALS AND

METHODS

The study participants (n = 150) were divided into three groups according to age at cochlear implantation: Group 1, 12-24 months; Group 2, 25-36 months; and Group 3, 37-48 months. The effect of age at implantation on auditory perception and language development performance was compared between these groups. The participants were also classified into five groups according to duration of cochlear implant use: Group 1, ≤48 months; Group 2, 49-72 months; Group 3, 73-96 months; Group 4, 97-120 months; and Group 5, ≥120 months. The effect of cochlear implant use duration on auditory perception and language development performance was compared between these groups.

RESULTS

A statistically significant weak negative correlation was found between age at cochlear implantation and scores on Glendonald Auditory Screening Procedure (GASP) and Preschool Language Scales Fifth (PLS-5; p < 0.05). A statistically significant weak negative correlation was observed between age at cochlear implantation and Speech Intelligibility Rating (SIR), speech discrimination tests, and pure-tone thresholds (p < 0.05). Scores obtained from the GASP, Categories of Auditory Performance (CAP) and SIR, and the PLS-5 tests differed significantly across groups defined by chronological age at implantation (p < 0.05). Scores on the GASP, CAP, SIR, PLS-5, speech recognition threshold, and speech discrimination tests differed significantly according to the classification by cochlear implant experience (p < 0.05).

CONCLUSION

The timing of cochlear implantation, together with individual differences, appears to impact long-term language development in children. To increase the chance that children using cochlear implants will achieve language development comparable to their normal-hearing peers, early implantation is important. Additionally, bilateral cochlear implantation, increased number of auditory-verbal therapy sessions, and long-term language intervention are critical. Children who undergo delayed cochlear implantation in particular require more intensive auditory-verbal therapy services.