Maybe he uses one of those speak-to-text translator utilities? And a lot of deaf people don't speak too clearly (I've heard some deaf people talk, and though I could usually understand them well enough, it was still sometimes hard to make out some of their words). But, not sure why that would affect typing words on a keyboard (unless the guy is like crippled up in a wheelchair too and doesn't have much functionality of his hands so much?). Man, now I feel bad, he could be like a deaf Stephen Hawking type dude. My respects go out to you if that's the case.
