I'm trying to speedrun the game Stuntman (PS2), and it's really difficult. Today I finally got a good run to submit, but when I went to check the video footage, there was no sound! I think it has something to do with my home theater and HDMI-ARC. The system was muted most of the time because I'm tired of listening the director calling "CUT! TOO SLOW!", it was driving me nuts! 

I record my video using an USB HDMI capture card and I also film the screen of the TV with a webcam while I'm playing. And there is a timer on the screen aswell. Just the sound bugged.

Is my run valid to submit? It took me a LOT of patience and effort to get the run going. I don't want to lose it. 

I've sent a message to @mirdo 

He's the moderator on the stuntman board. But I would like some feedback from anyone if possible. Thanks.

The answer to your question varies from game to game, some games require game audio to be recorded while other games don't. You should always check the rules of the game, and then contact the moderator for that game if you need clarification.

The rules for stuntman (ps2) don't mention game audio so you should be fine.