What the heck is that annoying buzzing sound accompanying ESPN2's coverage of the Brazil v USA soccer match today?

Along with the video feed of the FIFA Confederation Cup Group B game, on this very minute (it's 3-0 Brazil after 81:21), comes what sounds like the noise of a swarm of very angry bees, never varying in pitch or constancy.

I've noticed this before during soccer games at the world-class level but never this loud, so much so that I'm almost tempted to turn off the audio, not that the U.S. coverage is all that entertaining or informative.

Messi?

Kaká?

Anyone?