How to switch audio streams?
1. Touch the screen while the video in playback mode to show the app's toolbar.
2. Press the Settings 
button in the lower left corner.
3. Choose Audio streams and select the required.
Note, that you can choose the soundtrack by default in the Settings section.
Choose Playback→Default soundtrack→choose the language of the soundtrack.
If default soundtrack is not available for current video, the video plays with the first available soundtrack.
