CHANGE Feasibility Study

Inclusion Criteria: 1. Meet current cochlear implant indications at the implanting centre 2. In addition to meeting current cochlear implant indications, subjects must also possess preoperative unaided hearing thresholds between 40 to 65 dB HL at 250 \& 500Hz in the ear to be implanted. 3. Fluent speaker in the local language used to assess clinical performance 4. Eighteen years of age or older at the time of implantation with no upper age limit Exclusion Criteria: 1. Evidence of hearing loss prior to 5 years of age. 2. Sensorineural severe-to-profound hearing loss greater than 20 years at 2 kHz and above. 3. Simultaneous bilateral cochlear implantation or prior cochlear implantation in the ear to be implanted. 4. Additional disabilities that may affect the subject's participation or safety during the clinical investigation. 5. Medical or psychological conditions that contraindicate undergoing general anaesthesia or surgery. 6. Ossification, malformation or any other cochlear anomaly, such as common cavity, that might prevent complete insertion of the electrode array, as confirmed by medical examination. 7. Hearing impairment due to lesion or neuropathy of the acoustic nerve, VIII nerve or central auditory pathway. 8. Active middle-ear infection, 9. Tympanic membrane perforation 10. Unrealistic expectations on the part of the subject, regarding the possible benefits, risks, and limitations that are inherent to the surgical procedure(s) and prosthetic devices 11. Unwillingness or inability of the candidate to comply with all investigational requirements. 12. Patients with existing CSF shunts or drains, existing perilymph fistula, skull fracture or CSF leak. 13. Patients with recurrent episodes of bacterial meningitis.