Active noise control systems are becoming commonplace these days, but I do wish we could get a better overview of how the different systems work. Some manufacturers tout them as a major added feature, while other vehicles have them and almost nobody is aware of the fact.
But the last time I read into the technicalities of such systems, I came to understand that current ANC systems mostly only work well against predictable and lower frequency noises. Lower frequencies are mostly the target because they're really the only ones that can be cancelled out in a large open cabin where occupants can be sitting in a variety of positions. It comes down to the literally physically longer wave length of low frequencies, making it easier for ANC systems to generate a sound wave completely out of phase, or in other words the inverse wave as it travels through the cabin. Higher frequencies would take many more microphone locations and much faster processing/reactions from the ANC system to not risk actually amplifying sounds instead of quieting them.
Predictable noises are easier to cancel because they don't take real time reactions to changes is sound... they know our engines with VCM will produce 'X' frequency at 'X' phase and amplitude and given they know the exact source of the sound (the engine block) they even know the exact position of the sound waves as the enter the cabin.
All that to say that the main reason ANC exists these days is to reduce boominess from 4 cylinder engines or V6 or V8 engines running on 3 or 4 cylinders. But I'm sure technology has improved over the last few years to where they can also cut out some of the more persistent low frequency road noise. Wind noise is unlikely to be effected as it's too high pitch and unpredictable. But I'm sure in another 10-20 years you'll be seeing systems that can even reduce the sound of random rain drops hitting the windshield and roof.
Pretty cool technology with a lot of future potential, and one of the best things of all about it is that it doesn't theoretically add much cost to a vehicle since it uses the stock stereo system... it just needs a few microphones and an extra sound processor or two. That cost could be more than made up in reduced sound deadening materials... and that would also help vehicle weight.
