As my father in law's Parkinson's has progressed he is getting harder to understand when he speaks. Currently, I help with his telephone calls by repeating what he says to the caller. It makes sometimes for slow conversation but this way he can still use the telephone. His voice is getting softer and his words are not as clearly enunciated. Should I expect that he will eventually lose his ability to talk? If so does anyone have ideas on how he can communicate? He already can barely sign his name, and I don't think sign language would work with his shaking. He is still mentally quite sharp and his hearing is excellent. I'm open to ideas.