Originally Posted by Dan JGC
As far as I know....the second is just a slightly different laminated glass which doesn't transmit as much noise through the glass and the first must have something to do with noise canceling on some level. Probably noticeable if pointed out but the Summit is already very quiet without them. More of a quiet cabin refinement I suppose.
Most active noise cancellation picks up noise, then reverses the phase and plays back parts of that noise using the audio system or separate speakers. Trick is that it needs to consider the different wavelengths differently as to how to handle this for the various seating positions. There are very sophisticated tactics, or just brute force narrower band ones.
Active sound management is similar, but usually taps power train noises from around the power train and feeds it into the vehicle interior. Sorta like sticking cards in your bike spokes, but much more expensive.
Bose is a leader as are some ex-bell labs folks.