Why can't I play the audio files in the Klett Sprachen App? 25 June 2021 12:47 Updated The volume might be turned off. Check to make sure the loudspeaker volume is on. Related articles How can I purchase a digital edition for the Klett Sprachen App? Do you know the Klett Sprachen App? Why can't I download/see the content in the Klett Sprachen App? How can I order a class set? What are access codes and where do I enter them?