When watching media stream networks such as YouTube, Netflix and others without a wireless headset I experienced latency sound issue where there was a approximately 2 secs speech lag between video and sound.
This was resolved by the following actions:
1: Go into settings
2: Select Apps
3: Search the media app with the issue
4: Select the force stop button at the bottom right.
5: Go into storage of the icon and select clear cache button at the bottom right.
I hope the above mentioned helps