To change the audio language of a video on Smart TV's / Media Streaming Devices, follow the steps below:
If you're using an Android TV / Amazon Fire TV Stick / Xiaomi TV:
1. While watching a video, tap any arrow key on your remote, or the pause button to bring up the player controls
2. Select 'settings' (Cog icon) on top right corner
3. Select your preferred Audio language under the Audio language section
If you're using a Samsung TV / LG TV / Vewd TV / Sony CEB TV:
Unfortunately, selecting an audio language isn't an option on these devices currently. Only the default audio will play.