Investigation of the effect of head movements on sound localization in children with bilateral cochlear implants

Children with bilateral cochlear implants have difficulty sound localization in situations such as background noise, reverberation, and distance. The effects of head movements can be investigated on localization with developing technology. The aim of this study was to examine three-dimensionally localization ability in simultaneous and sequential bilateral cochlear implant users at different angles, distances and directions under head mobile and immobile conditions and to compare them with their normal hearing peers. For this purpose, the three-dimensional sound localization abilities of the participants were evaluated with the virtual reality system under head mobile and immobile conditions by calculating three-dimensional errors. The study included 14 children with bilateral sequential cochlear implants, 18 children with sequential cochlear implants and 21 children with bilateral normal hearing between the ages of 6 and 14 who passed the Moxo Attention Test. Children with bilateral cochlear implant and bilateral normal hearing were evaluated in the front and back hemifields around an arc surrounding them and the percentages of front-back confusion were calculated. As a result of the study, a significant difference was found between the three-dimensional localization abilities of the normal hearing group and the study groups in terms of azimuth error, front-back, right-left, overall three-dimensional error and percentage of the front-back confusion in both listening conditions (p<0,001). A significant difference was found in terms of azimuth error, overall error and percentage of the front-back confusion between head mobile and immobile conditions in the Virtual Reality Localization Test (p<0,05). There was no significant in the perception of the close distances evaluated in all three groups (p>0,05). In the present study, it was concluded that head movements improved three-dimensional sound localization abilities. Future studies might evaluate the change in localization ability by including head movement in auditory rehabilitation.