A deaf person cannot fulfill mitzvoth that specifically require hearing, such as Shofar.
If that person receives a cochlear implant so that he can now hear, other than, most likely saying "Hatov Vehamaitiv", is there some other appropriate blessing or prayer that he can or should say now that he is able to perform mitzvoth that he was never able to perform before?
If he does say a blessing should it be said immediately after receiving the implant as a means of appreciating the mere ability to perform the new mitzvoth, or should he say it immediately preceding or following the actual performance of the 1st "new" mitzvah?
The above is an example. You can apply the same idea to a blind person's receiving a new eye, and numerous other similar examples.