If he's really into the sound, why buy noise-cancelling headphones. I think they compromise sound quality. If good sound is the goal, buy good headphones form Shure, Sony, Sennheiser, Grado, Klipsch... NC headphones sample outside noise and mix in a signal out-of-phase to cancel it. I don't think the process is all that precise and cancels more than what's needed. I'm sure there are some better than others. A good set of headphones/earbuds with good isolating properties, I fell would be better for sound quality.