Binaural Fusion Sharpens on a Scale of Octaves During Pre-adolescence in Children with Normal Hearing, Hearing Aids, and Bimodal Cochlear Implants, but not Bilateral Cochlear Implants

Binaural fusion sharpens significantly on the scale of octaves in the age range from 6 to 14 years. The lack of change in interaural pitch discrimination with increasing age rules out discrimination changes as an explanation for the binaural fusion range changes. The differences in the trajectory of binaural fusion changes across groups indicate the importance of hearing device combination for the development of binaural processing abilities in children with hearing loss, with implications for addressing challenges with speech perception in noise. Together, the results suggest that pruning of binaural connections is still occurring and likely guided by hearing experience during childhood development.