Preliminary feasibility outcomes from 4 enrolled participants met expectations. Following a serious adverse event that is unrelated to the investigational device/procedures, a risk-benefit assessment determined additional enrolment was not justified.

The goal of this clinical trial is to compare speech perception and user satisfaction between two sound paths, Nuc8 (Cochlear Nucleus sound path) and Neu2 (Neuro 2 sound path), in adult users of the NeuroZti cochlear implant.

Following Cochlear's acquisition of Neurelec, there is a need to support existing NeuroZti implant users who currently rely on the Neuro 2 sound processor. The Nuc8-based sound processor, currently in development, is designed to be compatible with the Neuro system while integrating with Cochlear's ecosystem of tools and applications developed over the past decade.

To ensure long-term support and maintainability, transitioning to the Nuc8 sound path is preferred. However, changes in sound paths may impact sound quality, speech perception, and user acceptance.

The main question this study aims to answer is: how does speech performance and user satisfaction compare between the Nuc8 and Neu2 sound paths?

Participants will:

• Undergo speech perception testing in quiet environments
• Provide ratings on comfort and overall satisfaction

The study involves a single visit lasting approximately 3 hours.

Inclusion Criteria:

1. Aged 18-75 years old at time of consent.
2. Post-lingually deafened.
3. Bilaterally or unilaterally implanted with Oticon Medical Neuro ZTI cochlear implant, using Crystalis with autoXDP (GMCI 'CAP') as the main program, at 500pps stimulation rate. For bilateral CI users, only first-implanted side will be tested.
4. Fluent in French as determined by the investigator.
5. Willing to participate and comply with requirements of the protocol
6. Willing and able to provide written informed consent.

Exclusion Criteria:

1. Additional health complexities that would prevent or restrict participation in the evaluations, including significant visual impairment and/or cognitive impairment.
2. Subjects who have life sustaining devices (such as pacemakers).
3. NeuroZti Subjects with Antenna SD Type.
4. Unable or unwilling to comply with the requirements of the clinical investigation as determined by the Investigator.
5. Investigator site personnel directly affiliated with this study and/or their immediate families; immediate family is defined as a spouse, parent, child, or sibling.
6. Cochlear employees or employees of Contract Research Organizations or contractors engaged by Cochlear for the purposes of this investigation.
7. Pregnant or breastfeeding women.
8. Current participation, or participation in another interventional clinical study/trial in the past 30 days, involving an investigational drug or device (unless Cochlear sponsored and determined by investigator or Sponsor to not impact this investigation).

Cochlear do not have an approved platform for public sharing of IPD collected in this study. Data may be provided to individual researchers on request.