Anatomy Based Selection of CI Array for SSD Patients

Inclusion Criteria: * 18 years of age or older at the time of implantation * Unilateral severe to profound sensorineural hearing loss, as defined by a pure-tone average (500, 1000, 2000, and 4000 Hz) of 70 dB HL or greater * Normal hearing mild hearing loss in the non-implanted ear, as defined by a pure-tone average (500, 1000, 2000, and 4000 Hz) of 40 dB or less * Deemed an appropriate candidate by the investigator * Fluent in English Exclusion Criteria: * Duration of profound hearing loss of 10 years or more * Sudden onset of hearing loss within six months of implantation * Evidence of non-functional cochlear nerve using appropriate imaging modality to be determined by the investigator * Other retrocochlear hearing loss * Evidence of severe cochlear malformation (i.e., common cavity or ossification) * External or middle ear infection * Suspected developmental or cognitive concern * Other medical contraindication for surgery or anesthesia