That's a really interesting observation, I think you've got a good point there. Blindness seems to have a role in some folklore and fantasy -- Billy Blind, the blind seer of Krull, etc. I'm really just guessing here, but I wonder if people perceive blindness as being more isolative -- and therefore mysterious -- than deafness.

Also, I think there's maybe a cultural perception that deafness is touchy in general. Like, there's no way to handle it right, so we just don't go there. I think in reality, as with all things, some folks are just touchier than others, but my perception is that it's just too easy to offend someone if you try to "do" deafness. But if that barrier isn't a realistic one, it would be interesting to see it broken down.