Ambience or Room Tone- pertains to the pervading atmosphere of a place. (Often more of a psychological, rather than technical description)  Ambience is widely used as a synonym for ambient sound. Ambient sound consists of noises present in the environment.   In film and video sound production term Ambience usually means the background sound accompanying a scene.   Ambience is used for background sounds.  Sound recorded without dialogue on the location or set to be used to bridge gaps in the soundtrack .