"Outside noise" refers to any distractions, disturbances, or irrelevant information that can interfere with focusing or paying attention to something important. Full definition
It drove nicely without a lot of outside noise coming into the car when driving the highways. (cars.com)
And the engine can get a bit loud too, although the cabin is moderately well insulated from outside noise. (motoring.com.au)
Instead, lock him in a room without windows and turn the TV or radio on loud enough to block outside noises from coming into the house. (professorshouse.com)