If you had loudspeakers on the outside of your head, and passive attenuation in your ears, yes that would reduce pressure for you, but everyone else would have experience an increase. But adding more pressure in the cavity of your ear to reduce pressure makes very little sense.
Holy shit, buddy. Yes. We flip a signal 180 degrees out of phase and that added pressure pushes the outside wave down. There is at no point a reduction of pressure in your ear, it’s just more pressure that makes it so you can’t hear the sound you are trying to remove. The perception of sound and air pressure are not the same thing.