The aim of this clinical investigation is to demonstrate the performance, clinical benefit and safety of commercial cochlear implant systems. Speech performance and subjective hearing results, and comparison with cochlear implant results available in literature, is intended to demonstrate the performance and clinical benefit of the cochlear implant systems investigated in this study.

Inclusion criteria:

• Aged 18 years or older (at time of consent).
• Clinically established post-linguistic moderately severe to profound sensorineural hearing loss, in the ear to be implanted.
• Compromised functional hearing with hearing aid(s) or unlikely to receive benefit with hearing aid(s) in the ear to be implanted.
• Cochlear implant candidate as determined by the Principal Investigator. Meets local candidacy criteria for cochlear implantation.
• Candidate is a fluent speaker in the language used to assess speech perception performance.
• Willing and able to comply with study follow-up schedule.
• Willing and able to provide written informed consent.
• Candidate has access to a Smartphone compatible with Nucleus Smart App.

Exclusion criteria:

• Prior cochlear implantation in the ear to be implanted.
• Unrealistic expectations regarding the possible benefit, risks and limitations that are inherent to the surgical procedure and prosthetic device as determined by the investigator.
• Any contraindications for cochlear implantation listed in the relevant product physician's guide (to be specified per sub-investigation).
• Unable or unwilling to comply with the requirements of the clinical investigation as determined by the Investigator.
• Investigator site personnel directly affiliated with this study and/or their immediate families; immediate family is defined as spouse, parent, child or sibling.
• Cochlear employees or employees of Contract Research Organisations or contractors engaged by Cochlear for the purposes of this investigation.
• Women who are pregnant.
• Current participation, or participation in an 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).

Post lingually deafened adult adults who are a candidate for cochlear implantation.