I think the 850 is really comfortable, but the noise cancelling feature doesn't do much. The weird thing about this headset is depending on which airplane you are in, will determine if you can keep the hot mike on. Sometimes I can leave it on for the whole flight, but in some planes the mike drives me crazy after about 2 minutes from the wiper noise. But to answer your question, no turning off the IC will not turn off the noise cancelling. There is a switch on the headset to turn it on or off.