Garry's Mod No Sound

I usually am capable of solving these issues, but I have been unable to for the past three days with this one. I launch Garry’s Mod and I hear no sound coming from the game. I am currently listening to iTunes so it isn’t an issue with my computer. I have verified integrity of
game cache, no luck. If anyone is able to help me it would be greatly appreciated. Thanks in advance!

Check your volume options in game, check your Windows Mixer volumes.

I must have lowered game volume and forgotten. Thanks for helping me out!