"Ambient noise" refers to the background sounds that are constantly present in any environment, such as traffic noise, people talking, or the hum of appliances. It is the noise that we often hear when there is no silence. Full definition
Unfortunately, the use of surrounds was lacking, and we really didn't hear a lot of ambient noises in the background that could have immersed us into the film more. (dvdtalk.com)
But a little ambient noise in workout headphones can be a good thing, especially for outdoor runners. (theverge.com)
But when you're walking around outside, the bass sounds toned down because it's competing with ambient noise, whether it's the wind or traffic or whatever. (cnet.com)