Figured I would post my context to the situation since there's a lot of conflicting info on reddit. Here's my POV:
The only sound in our headphones was hearthstone music/game sounds (no white noise).
Big thing is that LVGE hovered and pulled the Dirty Rat out of his hand, then put it back. After he grabbed the card, the Chinese casters went crazy and it was very easy to hear them. After the casters yelled, LVGE threw out the rat. You can clearly see him hovering it out of his hand in this clip: https://clips.twitch.tv/firebat/PlainTigerJKanStyle
I didn't see if the Chinese team said anything but my team said they were being very loud discussing whether Ooze or Rat was the play that turn.
After the play, I actually yelled at the casters "Yell louder next time, I couldn't hear you well" sarcastically. It feels hopeless to call an admin when you know nothing will be done about these situations (my team contacted the admin to complain), and the game was pretty much lost for me at that point. Anything short of a gameloss/regame was pointless as the game was tournament point for the Chinese.
Anyway, we reported our complaints to the tournament staff and they will hopefully improve things in the future. Not much more to be done, congratulations to the Chinese team on an otherwise well played tournament. And thanks to the staff for making our stay in China great.