Spot on!
Regarding your question: good ones to which I have no answer. I suppose the only way to find out is to try yourself.... not sure how one can become deaf though without permanent staying in such state.... we shall get this chips brain implants, maybe then we have a tool to control the state of our hearing, switch it on/off as we please.
Hmmm, interesting idea. Well, not an average idea, for sure. Although I see the way that those implants can really work, to improve the hearing, or make up for the lack of sensation of hearing, it is pretty difficult to imagine we could turn off our senses with one click. But it would come in handy, sometimes :)