Q:
HDMI to TV but no sound?
As a quick suggestion, if all of your audio is coming through the tv, open your in-game options panel, go to sound options, the check what options are available. Have a tinker with those and see.
I think different cables use different options, so if everything else is working, that’s all I’ve got off the top of my head.
Is this from a Macbook or similar using a Miniport to HDMI adapter? If so then it is not possible to get sound through the TV as miniport doesn’t support it to my knowledge. You would need to also run the sound out from the Macbook.
As far as I know, the official Apple answer to this problem is “use Airplay”.