Don't think the marshals would be down with it, you'd be at risk of failing to hear things like man-down calls, game end calls etc...I don't doubt you're smart enough to keep an ear out, but most sites go for 100% certainty! The best bet would be to ask the guys running the day!
See again, I'm sure you'd be perfectly safe with it, but the marshals at the site probably wouldn't go for it, when it comes to safety, you've got to be 100%. Plus yano, the best battle music is James Blunt anyways...