To what do you reference Rush's statement that if he had an implant, it would also entail "brain surgery" ? Is that description consistent with this type of operation?
It's not accurate. The brain is not exposed. We make a small hole in the cochlea, called a "cochleostomy", in order to access the hearing nerve fibers.
We should forgive Rush this minor inaccuracy. Chalk it up to him going through a period of adjustment like we all would if we were suddenly informed we had a life-changing disability, and you become as much an expert as you can at first, but there is much to learn.