ambiance (film sound)   

The overall quality of a location.
Elements include (but are not limited to) locationís reverberation characteristics, atmospheric sounds such as wind, machine hum, mechanical noises, etc. For each new location, the recordist should record at least two minutes of ambiance.  Since all of the apparatus of production contribute, this should be done with everything in place for shooting the scene.  

Ambiance may also refer to the overall sound quality which the designer is aiming for.