I think it has something to do with altering sensory input. It doesn't even have to be auditory input necessarily. For instance if you were to poke yourself with thumbtack (not recommended) it might get you past a repetition or block. Accents, singing, choral reading--these can help some people some of the time. I had an idea about singing. I wonder if it would work to think in terms of a singing, but not be obvious about it. For instance, if I know I'm coming to a word I'm going to struggle with, to think of that word as a note in a song, and just sort of secretly sing the problem word--like some sort of singing talking hybrid.