Depends on the model. QC20's from bose (in-ear noise canceling) are basically magic in that regard - turn them on, add relatively quiet music, and I might as well be deaf to everything, including conversation.

That does lead the the annoying problem that I have to have something stuck in my ear (vs on, which isn't quite as annoying) for 6ish hours a day. Also, they're expensive af, and require frequent charging since I never remember to turn off the noise cancelling when I'm done with them.