After playing Sum6 for about 30 minutes I remarked that the sound started to deteriorate, with lot of crackles and rumble. This is not just the background music, but also with dialogues and effects.

I had to quit the game as it became very annoying. BTW, lowering the volume in game (our out game) doesn't help. It simply sounds overloaded.

Gonna try some sound settings and restart the 'puter to see if I can avoid the problem.

Hi, one of the devs here (and currently actually on vacation to recover from the weeks leading up to release).

We're aware that this happens on some systems but sadly haven't been able to fix it so far, though we will keep looking into it. System specs might help us in identifying the causes.

The only potentially useful thing I can say for now is that you don't have to restart the entire game, in my experience going to the main menu and loading the game is enough to fix the issue. Might save you some time.