Auditory Intranerve Stimulation Perceptual Study

Scientific Assessment of Auditory Intranerve Stimulation Loudness and Pitch Percepts

The objective of this scientific study is to evaluate the feasibility of direct auditory nerve stimulation to elicit key percepts, specifically loudness and frequency/pitch percepts in three deaf patients participants with the new auditory nerve implant (ANI). During the year with temporary stimulation of the auditory nerve, patients participants are expected to participate for 14 months, consisting of: two months for surgery for the nerve implant and healing phase, one month initial follow-up, ten months of follow-up care and study testing, and one month for explanation and post-operative observation.

The auditory nerve implant (ANI) targets the auditory nerve directly between the cochlea and the brainstem, whereas current implants like the cochlear and brainstem implants stimulate the cochlea or brainstem, respectively. By providing direct stimulation within the auditory nerve, a nerve implant offers a better electrode-nerve interface and may achieve improved hearing compared to a cochlear or brainstem implant. Preliminary results in animals, computer simulations, and acute clinical studies showed significantly better performance compared to other hearing aidsoptions. This study aims to investigate the extent to which these benefits are perceptible in the human auditory nerve.

The primary goal of this study is to gain scientific insight into the hearing experience with the direct auditory nerve stimulation. However, the results could contribute to the development of new hearing implants that directly stimulate the auditory nerve.

Inclusion Criteria:

1. Age ≥18 and ≤85 years

2. Written informed consent

3. Bilateral deafness with cochlea that does not allow the implantation of a cochlear implant (CI). This can include ossification, malformation of cochlea; poor CI performers (lowest quartile of CI performance); and patientparticipants with facial nerve stimulation using a CI which is not manageable without reduction of performance

4. Eligible for routine auditory brainstem implant (ABI) where patientparticipants would undergo more invasive brainstem surgery than the ANI surgery

5. Functional auditory nerve and central auditory pathway

6. Post-linguistic onset of ipsilateral severe-to-profound hearing loss

7. The contralateral ear has sufficient vestibular function

8. Women not able to become pregnant*

   • Women not able to become pregnant defined as follows:

     • at least 6 weeks after surgical sterilization by bilateral tubal ligation or bilateral oophorectomy or
     • hysterectomy or uterine agenesis or
     • ≥ 50 years and in postmenopausal state > 1 year or
     • < 50 years and in postmenopausal state > 1 year with serum FSH > 40 IU/l and serum estrogen < 30 ng/l or a negative estrogen test, both at screening

Exclusion Criteria:

1. Medical, neurological, or psychological conditions that would contraindicate undergoing surgery, e.g. depression, acute cardiac infarction, history of stroke, dementia, epilepsy
2. Additional handicaps that would prevent participation in evaluations
3. Women able to become pregnant
4. Pregnant women
5. Persons who are deprived of their liberty on the basis of an official order or a court order or authorization
6. Known allergies to one of the components of the implant (medical grade silicone, Parylene-C, Iridium oxide, Platinum-Iridium alloy (PtIr 10) and (PtIr 20) )
7. Other active devices with potential interference with the auditory nerve implant
8. Presence of anatomic abnormalities that would prevent appropriate placement of the stimulator housing in the bone of the skull
9. Additionally, in the event of other health issues, the investigators will decide on a case-by-case basis whether to enroll the patientparticipant in the study