Ray,
the return of sensation can take a while. It thought it was pretty good after the surgery, but then the radiation poured it on again. It took quite a while after that for the feeling to return to something near normal..... or what is perceived to be normal.
Even if the feeling comes back that does not mean that everything will be as before, you are missing a portion of your tongue and that affects the sounds you can make, especially until you adapt and learn to compensate.

M