Evaluation of a HiRes™ Optima Sound Processing Strategy for the HiResolution™ Bionic Ear

Inclusion Criteria: * Unilateral or bilateral user of CII/HiRes90K™ implant(s) (minimum of one year in each implanted ear), Harmony™ BTE processor(s) with HiRes Fidelity 120™ (with or without ClearVoice™) as preferred sound processing strategy * 18 years of age or older at time of implant * Postlingual onset of severe-to-profound hearing loss (≥ 6 years of age) * At least moderate open-set speech recognition abilities (defined as CNC word score ≥ 50% in medical records or assessed at the Baseline Visit with implant alone for unilateral users, with both implants together for bilateral users) * English language proficiency * Willingness to use a Harmony™ BTE processor and refrain from ClearVoice™ use for the duration of the study * Willingness and ability to participate in all scheduled procedures outlined in the protocol Exclusion Criteria: • Presence of any additional disabilities that would prevent or interfere with participation in the required speech perception testing