Dexamethasone-Eluting Cochlear Implant Electrode

Inclusion Criteria: * Minimum age of eighteen (18) years at time of enrolment. * Severe to profound sensorineural hearing loss on the ipsilateral ear. * A functional auditory nerve in the ear to be implanted. * Subjects reporting to having used an optimally fit hearing aids for a minimum of three months before the decision that a cochlear implant (CI) is the preferential option. * Cochlea anatomy compatible with the insertion of a +FLEX28 electrode array. * Compatibility with a soft surgery approach as per clinical practice at the site. * Post-lingual hearing impairment. * Subject fulfilling indication criteria for a CI according to the local professional standards, as reported by the implanting surgeon. * General health condition, psychological and emotional condition deemed compatible with the treatment and tests performed in this study and realistic expectations, as deemed appropriate by the implanting surgeon. * Signed and dated informed consent before the start of any study-specific procedure. Exclusion Criteria: * Lack of compliance with any inclusion criterion. * Previously having received a cochlear implant on the ear chosen for placing the IMD (Investigational Medical Device). * Evidence of ossification or any other cochlear anomaly that might prevent complete insertion of the electrode array or might cause increased risk of infection (e.g. dysplastic cochlea), as confirmed by medical examination and/or as per CT/MRT (Computed Tomography/Magnetic Resonance Tomography). * Evidence of anatomic abnormalities that would prevent appropriate placement of the stimulator housing in the bone of the skull. * Evidence of otosclerosis. * Known allergic reaction or intolerance to the materials used in the implant (including medical grade silicone, platinum, iridium, parylene c, dexamethasone). * Known absence of cochlear development or if the cause of deafness is non-functionality of the auditory nerve and/or the upper auditory pathway. * Evidence of active external or middle ear infection or history of recurrent middle ear infection in the ear to be implanted. * Evidence of perforated tympanic membrane in the ear to be implanted. * Patient reporting immunosuppressive therapy or corticosteroids therapy in the 4 weeks before enrolment. * Evidence of concomitant use of medicinal substances that, in the opinion of the investigator, could alter the therapeutic efficacy of dexamethasone. * Unwillingness or inability of the candidate to comply with all investigational requirements. * Evidence of medical contraindications to surgery of the middle and inner ear and anaesthesia. * Additional disabilities that would prevent or restrict participation in the audiological and medical evaluations required of the clinical investigation.