There's just something very, I dunno, visceral? about hearing words as opposed to seeing them. Especially your own words, in a voice different from the one you've been hearing in your head. And if they are porny words, well....

Are you listening to a recording, or are you actually there in the room while he's reading? I don't think listening only would bother me all that much, but I would probably die of acute embarrassment if I had to make eye contact OMG