Children with sequential bilateral cochlear implants: Effects of inter-implant interval between implants on auditory-verbal memory skills in quiet and noise

Objectives: The purpose of this study was to investigate the effects of the inter-implant interval and listening condition on auditory-verbal memory skills in children with sequential bilateral cochlear implants (CIs) and to assess if inter-implant interval between implants would predict their auditory-verbal memory skills in quiet and noise. Methods: Fifteen children with unilateral CIs, 15 children with short range interval between implants (SRI), and 15 children with long range interval between implants (LRI) participated in this study. Children with CIs received the first CI before 3 years of age, and their age at testing ranged from 6 to 13 years. In the auditory-verbal memory tasks, children were asked to immediately repeat the final words of auditorily represented sentences, and then rehearse the words for subsequent recall. Results: All three groups showed significantly better performance on the two tasks in quiet than in noise. Children with SRI recalled significantly more words in noise than children with unilateral CIs and children with LRI did. Auditory-verbal memory skills in noise were significantly correlated with age of the second CI, duration of the first CI, and inter-implant interval between implants in children with bilateral CIs. The inter-implant interval between implants was a significant factor predicting auditory-verbal memory skills in noise in children with bilateral CIs. Conclusion: These results suggested that a shorter inter-implant between implants may positively impact on auditory-verbal memory skills in children with bilateral CIs. Inter-implant interval between implants may play a critical role to predict auditory-verbal memory skills in children with bilateral CIs.