Comprehensive reply by @Deaf_piper on Australian health insurance!
Though, do check the policy regarding hearing aids. I’m with BUPA too, and they do cover some of the cost of purchasing a hearing aid (which I discovered long after the purchase of my last aid before going CI). Waiting periods apply also.
Side-stepping a bit, also consider having contents insurance with the CI covered as a specific item in case it gets damaged and needs to be replaced. More so initially when you only have one of them.