[GAMEPLAY] No Sound While In-Game

I've had this problem before, and it went away after uninstalling and reinstalling the client. But after the most recent patch it seems to have become an issue again. Basically, I get sound using the client, and during champion selection and all that. But as soon as I get ingame, I lose all sound. It's particularly annoying because I sometimes browse the Internet during the loading screen and I rely on hearing the cold winds of the Howling Abyss to tell me to tab back into LoL. However, toggling and untoggling the "Disable All Sound" option in the Audio menu makes this problem go away for the duration of the game.

Steps to Reproduce:

1. Find a game
2. Go through Champion selection.
3. Load game.
4. All sound should be missing.

Steps to Temporarily Fix:

1. Go to Audio menu.
2. Toggle Disable All Sound on
3. Toggle it back off.
4. Sound should be back.