Yawn.
I've also heard that if you fart and sneeze at the same time, your eardrums will rupture.
It's never happened to me, because I am careful to only fart, then sneeze but I worry about all those irresponsible parents who feed their children foods high in polysaccharides.
In one case, a young child with a head cold ate a whole jar of sauerkraut and is now deaf. True story, I know the friend of the second cousin who plays cribbage with local parent of the kid it happened to.