The Sponsor values the progression of hearing healthcare practice and acknowledges a need for re-evaluation of indications for determining adult cochlear implant candidacy. This need arises from current research, peer reviewed literature, and technological advancement with concomitant performance outcomes. To address this specifically, the Sponsor proposes to evaluate the safety and efficacy of the Cochlear™ Nucleus® implant system with a revised indication.

Existing research, as discussed, supports the opinion that current candidacy criteria are set conservatively. The Sponsor, in addition to the support of recent peer reviewed literature illustrating a need for an appropriate criteria and more suitable speech recognition measure, believe it is appropriate at this time to re-evaluate the candidacy requirements associated with adult cochlear implantation. Specifically, this will be accomplished by evaluating the safety and efficacy of the Cochlear™ Nucleus® cochlear implant system under revised cochlear implant indications. The proposed approach would be to evaluate individuals scoring between 10 - 40% inclusively on Consonant Nucleus Consonant (CNC) monosyllabic words who do not meet current approved speech perception criteria with the widely used sentence measure Hearing In Noise Test (HINT) in quiet. No change to current qualifying audiometric criteria (bilateral moderate to profound sensorineural hearing loss in the low frequencies and profound hearing loss in the mid to high speech frequencies) for implant candidacy is proposed.

Inclusion Criteria:

• Eighteen years of age or older at the time of the study.
• Preoperative aided CNC word score in quiet of greater than or equal to 10% and less than or equal to ¬¬40% in the ear to be implanted; equal to but no better than 50% in the contralateral ear
• Bilateral moderate to profound hearing loss in the low frequencies (up to 1000 Hz) and profound sensorineural hearing loss in the high speech frequencies (3000 Hz and above)
• Willingness to use bimodal stimulation (i.e. a cochlear implant on one ear and a hearing aid on the contralateral ear) through at least 6-months postactivation.
• English spoken as the primary language.

Exclusion Criteria:

• Congenital hearing loss (for the purpose of this study, onset prior to 2 years-of-age).
• Preoperative aided HINT sentence score less than or equal to 50% in the ear to be implanted
• Ossification, absence of cochlear development or any other cochlear anomaly that might prevent complete insertion of the electrode array.
• Hearing loss of neural or central origin (e.g., deafness due to lesions on the acoustic nerve or central auditory pathway).
• Active middle-ear infection.
• Unwillingness and/or inability of the candidate to comply with all investigational requirements including, but not limited to, study protocol and surgical procedure.

Subjects who met study inclusion and completed the primary endpoint of 6 months postimplant activation.