Guarantee you I would've were that my child. She adapted very quickly to hearing again. IIRC from what my friend said, the doctors said going into the surgery to implant the cochlear device that since their daughter had hearing up to the time she was two, that she should respond quickly to "hearing again" ... the brain has a way of remembering speech I guess.
She's a teenager now and you'd never know she has that implant by talking to her. She hears and talks just like any other "hearing" kid.
Sorry. I’ve been called out as a liar on this.