Y was based entirely on audiometric criteria. Duration of high-frequency hearing loss, age at implantation, and etiology were documented, but not used as exclusionary criteria. Test Materials Auditory function was evaluated pre- and postoperatively at 3, 6, and 12 months using a common battery of speech perception measures. The CNC (Consonant-NucleusConsonant13) word recognition test and the BKB-S