I ordered these headphones for my wife who spends 8-10 hours a day wearing headphones. In her line of work, clear speech is paramount. The noise cancelling effect of these headsets is much better than the previous pair (also active noise cancelling), and I have noticed that when she's transcribing that I have to yell to have her hear me now. When I have used them, the first thing I noticed is the sound of the fan in her computer just vanished when switched on. It wasn't reduced, it was gone. While using them, sounds were crisp, and speech was crystal clear.
In fairness, I don't care about music, I only want to maintain harmony in the house, and for her, harmony is a set of headphones that make her work easier and more efficient. Harmony for me is a set that will last a couple years of hard use, and these Asus units seem to meet the bill.