As far as I can tell, it's just broken. Played a good amount of Battlefield 4 and took some video from the Share feature. When I went back to watch it, it was all silent. Just another thing that Sony is gonna have to fix at some point.
i tuned into a stream of jonathan blow playing resogun and im not sure if he just didnt want to change it but the volume of the womens voice in that game was way too loud . i could not stand it especially when trying to listen to him talking. there must be some settings, theyll do it in an update i bet