Mighty Linux Man: Do you have a separate sound card or on motherboard sound?
Do you have Nvidia card sound?
If you have both, which sound is the game using?
Can you switch from one to the other?
If so, does it make a difference?
TheWhlteWolf: I have motherboard sound only.
no, have amd.
I know it's not likely, but just to make sure the obvious has been covered before going further, have you rebooted the PC since the problem occurred? If there was a glitch or problem with sound in the game that happened as soon as you went into the game, it can sometimes fix itself with a reboot.
I am assuming you have no sound problems anywhere else such as Internet videos, music players, other games etc.
I also assume that you have no sound at all, including voice, music, speech, sound effects.
Another assumption is that your sound device is correctly chosen in the sound settings. Sometimes it gets changed without you knowing it has occurred. Are you using separate speakers or monitor speakers? Is that selected in the sound settings and is the volume okay?
Since your only sound card is your motherboard, have you updated or re-installed the video drivers and the HD audio driver that is included with them? A clean install of those drivers would probably be best to make sure there is no problem there.