tfabris carpal tunnel
Registered: 20/12/1999
Posts: 31618
Loc: Seattle, WA
You are referring to "active cancellation" and it's a very tricky business with very limited application. Unfortunately, it would not work with the empeg in the car because the road noise emanates from all around instead of just one point, and also the mic input can't sample high enough frequencies to get all of the noise.