A bilateral hearing implant system has a left side and a right side. There is an interaural time delay (ITD) processing module on each side that adjusts ITD characteristics of the stimulation signals based on defined groups of stimulation channels that include: i. an apical channel group on each side corresponding to a lowest range of audio frequencies up to a common apical channel group upper frequency limit, wherein a common number of one or more stimulation channels is assigned to each apical channel group, and wherein corresponding apical channel group stimulation channels on each side have matching bands of audio frequencies, and ii. one or more basal channel groups on each side corresponding to higher range audio frequencies above the apical channel group upper frequency limit.