I've never asked for these accommodations in a hotel mainly because I expect most TVs to have closed captioning (I know this is silly; hotels can have a universal remote that doesn't have a CC button or may use HDMI cables that can't transmit CC signal, but I assume it anyway) and don't use the other devices (TTY, visual alarms, etc) at home. Then again, I haven't stayed in that many hotels. If I were a more frequent traveler this would be something I would be thinking of.
It reminds me of my freshman year at Arizona State University. I asked for and received a room set up for disability accommodation - not just hearing impairments but for people in wheelchairs, etc. The two bedroom/living room setup was huge to accommodate wheelchair use, and it was awesome living there.