The AKG N700NC M2 have an adaptive ANC system that automatically adjusts its level to better suit the noise around you. They can block out bass-range noise, like the rumble of bus and plane engines, well, making them a solid choice for commuting and traveling. They also do an outstanding job of reducing ambient chatter and the high-pitched hum of AC units.
Note: These headphones have an ANC system that you can't turn off. To test passive noise isolation, we turned the headphones off.