Description of intervention(s) / exposure

The study will consist of 3 groups. The first group will have 5 participants, the other groups 4 participants each undergoing cochlear implantation. Both the placebo and FX-322 will be administered by intratympanic injection in the ear to be implanted. All participants will be injected once with an identical volume (0.2 mL)

into the middle ear. This injection will be performed by a specialist and qualified cochlear implant surgeon. The participants will differ in obtaining Placebo (12-24 hours prior to implantation) or FX-322 (18mg) and the time window for the injection

(either 12-24 hours prior to the surgery, 3-5 hours prior to surgery or 0.5-2 hours prior to the surgery). The exact time of injection is based on hospital logistics. Group 1 will have the first two participants allocated to placebo and three FX-322. .participants. Group 2 and Group 3 each will have one placebo participant and three FX-322 participants. The participants in each group is based on hospital logistics. There is no dose change

The reason for forming 3 groups is to have a safety review after each group

. The participants will all be followed 1-4 weeks after the cochlear implantation. Participants

must be adult and audiometric threshold of 80 decibel [dB] hearing loss [HL] or poorer at 500 Hertz [Hz])

