On US TV, (ABC/ESPN), the stupid horns are audible, of course, but much less so (to my ears) than during last year's broadcasts of the "practice" (or "shakedown") tournament held in South Africa.

Seems to me that the audio technicians found some kind of way to de-emphasize the background noise in relation to the main soundtrack (the commentators).

If I knew the sport really well (i.e., if I had grown up with it, like boys around the world outside the US), I'd probably turn the sound down/off. But as a casual and uninformed fan, I need all the information I can get. The current World Cup is providing an unprecedented amount of coverage, and I expect to learn a great deal about the sport by the time the Cup has been won.