Wikipedia has it right: "Coupe utility".

Seems to be a 'cover your arse' sort of thing. I listen to my iPod on the train on my way to work (1.5 hours each way); I work at an electric steel mill, which is loud even with ear protection; and I go to bars and pubs every now and again where the conversation and mood music (read: crappy dance/house shit) is nearly as loud. I reckon that if I'm still listening to an iPod 20 years from now, I'd be turning up the volume just that little bit more. If I were to go to court arguing that my iPod ruined my hearing, I'd never be able to prove it.

Then again, looking at the previous comment from Randavance (Dec 24th), looks like some people need this pretty quickly. But that's why I wear ear protection at work - 'prevention is better than cure'. Maybe Apple can also sponsor hearing health classes at high schools?