Our results suggest a significant influence of prelingual deafness but less impact of elderly age at implantation on long-term CI programming parameters and CI thresholds. The larger C levels and lower CI thresholds in the Prelingual group than in the Adult and Elderly groups implied that CI children with prelingual deafness tolerate and prefer larger CI stimuli, which may reflect the CI-dependent development of their auditory system before the critical period. No age-related reduction in hearing thresholds was observed in the Elderly group, probably because the CI compensates for age-related dysfunction of the peripheral auditory system.