Noise Cancelling - Again, shocked that some think the PXC 550 is on par with the Bose QC35. Pero cuando probe el microfono no me escuchaban mis amigos en el videojuego. Id love to give these 5 stars, but they only get 4 because they are not durable. The build at first glance looks premium. However, I bought these slippers in a size Large - which is supposed to fit a size 9-10 shoe - and they were perfect. Edit - dropped another star as I am constantly getting crackling even when the USB link is the only device connected to the headphones. Rated 3-stars to average out my initial 5-star opinion vs the 1-star for such a catastrophic flaw. Vents??? Theres no vents! The result is copy variation is VERY INCONSISTENT and a lot of internal elements that move around, break, or move out of position and alignment. I needed to try a center mount kickstand after one of the bolts on my side mount got sheared off.