Have you noticed how quiet Polish war films are?

This is just a thought, but why do Polish war films go quiet unless the characters are directly involved in the action. For instance, the Battle of Westerplatte was described by the Germans as a 'second Verdun' in relation to the artillery ordnance laid down. Yet in the film of the same name, unless the main characters are involved, utter silence. Same with Warsaw 44. Background sound tracks can't be that expensive. Or is it being 'artistic'? A low rumble of artillery or street fighting sounds behind the dialogue would add to the atmosphere and authenticity don't you think. Other than that nitpicking a sound and respectable movie, if a little arty farty in places.