목적: Normal-hearing (NH) listeners rely on two binaural cues, the interaural time (ITD) and level difference (ILD), for sound localization. Cochlear-implant (CI) listeners, however, rely almost entirely on ILDs. We wanted to determine whether significant improvements in sound source localization are achieved in cochlear implant (CI) recipients with single-sided deafness (SSD), a hearing aid (HA) in the contralateral ear (asymmetric hearing loss, ASHL) and bilateral CI recipients. 방법:This is a retrospective study of 10 CI recipients with NH in the contralateral ear(SSD), 15 CI recipients with a HA in the contralateral ear (ASHL), and 10 bilateral CI recipients. Sound source localization assessment was performed after at least 6 months from the date of cochlear implantation. Participants were asked to indicate the sound source for a narrow-band noise presented randomly at varied frequency (500 Hz and 4 kHz) and 65 dB HL stimulation levels from one of 7 speakers along a semi-circle. Localization performance was quantified as average error degree (AED) error and right-to-left correct discrimination ratio (RLD). 결과:Overall, bilateral CI group showed better localization abilities in AED and RLD at 500 Hz than the other groups and ASHL group showed the poor localization ability. Superior post-CI localization performance was obtained with CI use as compared to unaided localization abilities in SSD and ASHL groups. In both SSD and ASHL groups, a significant improvement in RLD at 4 kHz was observed in aided condition compared to unaided condition. A significant improvement in AED at 500 Hz and 4 kHz was observed in only SSD, but not in ASHL group. 결론:CI recipients experience significant improvements in sound source localization, as demonstrated in sound localization test. Our findings suggest that bilateral CI group uses ITD cues for sound source localization better than ASHL group, though some SSD group may use ILD cues as well.