Subtitles?

Are the German scenes meant to be subtitled? My dvd doesn't have them, but if you put on the subtitles for English Hard Of Hearing you get a translation, but as you need to go back to the menu screen each time it's not very practical. I wondered if it's a mistake or whether you were just supposed to get a sense of what the Germans were talking about from their behaviour and the occasional recognisable word, but some of the scenes did go on a bit.