 Many of the German soldiers in the movie were not Germans, but  Hungarians, Russians, Norwegians, Swedes, Americans, British and  Canadian people. Many of which were students from Universities from  around the Kansai area, like Osaka and Kyoto. Thus, when the  soldiers were going to shout and talk and make noises, only the  German people and people who could pronounce perfect, or good enough  German were allowed to say something.