It's easy to change audio tracks in VLC for the iPhone or iPad. Here's how you can do it if you want to choose a different language for the video you are viewing.
1. When viewing a video in VLC for iOS, tap the screen once.
2. Tap the speech bubble button that appears in the on-screen controls.
3. Tap the audio track you want to listen to from the list that appears.
Additional resources for VLC