Investigation of localization skills of bilateral cochlear implant user children

Binaural hearing supports the development of sound localization skills and allows the auditory system to perform optimally. It is known that bilateral cochlear implantation positively affects the development of sound localization skills. The aim of this study was to examine the sound localization ability in simultaneous and sequential bilateral cochlear implant users and to compare them with their normal hearing peers, and to investigate the effects of inter-implant interval on sound localization ability in sequential bilateral cochlear implant users with different inter-implant intervals. For this purpose, the sound localization skills of the participants were evaluated with the Auditory Speech Sound Evaluation (ASSE) test battery. The study included 19 chidlren with bilateral simultaneous cochlear implants, 21 children with bilateral sequential cochlear implants with an inter-implant interval of less than 4 years, 19 children with bilateral sequential cochlear implant with an inter-implant interval of 4 years or more, and 18 children with bilateral normal hearing between the ages of 4 and 18 years. Azimuth Localization Test and Interaural Level Difference (ILD) Localization Test were applied to all subjects, respectively. As a result of the study, a significant difference was found between the sound localization skills of the group with normal hearing and the other groups in the Azimuth Localization Test (p<0.05). In addition, in the ILD Localization test, a significant difference was found between the sound localization skills of the study group with more than 4 years interval between implants and the other groups (p<0.05). In children with bilateral sequential cochlear implant, correlations were observed between the inter-implant interval and the sound localization ability. In the present study, it was concluded that the inter-implant interval, chronological age and the type of interaural cue used in the localization assessment are important factors affecting the sound localization ability in children with bilateral cochlear implants.