OBJECTIVE: In children with bilateral cochlear implants(CIs): 1) quantify cortical access and sensitivity to inter-aural level differences(ILDs)
2) determine if cortical ILD detection predicts ILD perception
and 3) assess demographic and clinical factors that could limit ILD access. METHODS: Cortical detection responses evoked by ILD changes were measured in 22/24 children with bilateral CIs(7 female) using their clinically programmed devices and in 8 children(3 female) with normal hearing. Behavioral lateralization(left vs right perception) to ILDs was also measured. RESULTS: Increased cortical sensitivity(amplitude) to ILD changes did not predict more accurate behavioral perception
rather children with CIs were able to lateralize ILDs with fair accuracy but with increased cognitive effort(reaction times) compared to normal hearing children (p = 0.0004, Cohen's d = 1.17). While demographic factors did not significantly contribute to response measures, symmetry of programmed levels in the left and right CIs predicted better cortical and behavioral sensitivity to ILDs (ps <
0.05). CONCLUSIONS: the developing auditory system can detect ILD cues when provided with bilateral cochlear implants
however, this access can be altered by programming and may not translate to normal binaural processing. SIGNIFICANCE: There is potential for clinical programming to improve spatial hearing in children with bilateral CIs.