Games occasionally have no sound

Since the bug fix on September 4th, my games have sometimes started with no sound (although the there is sound in the lobby or any pregrame situation). Additionally, the notifications for kills show for a quick second before disappearing, and the same with allies destroying towers. Nothing I do to the sound controls in game, or my computers sound can bring the sound back for that game. When I do get a game with sound, there are no issues. I'm pretty sure it's just league, because I can have sound from other applications on my computer. Thank you for any help!