If all else fails, a complete reinstallation of Windows (or using a tool like DDU to wipe your audio drivers) is the final bomb strike. Until then, happy hunting, soldier. Your sound bank is waiting to load.
If the game insists on looking for "polish" files but you only have English ones (or vice versa), you can trick the game by renaming the files. Go to the folder inside your game directory. Black Ops 2 Sound Bank Failed To Load Cmn-root.polish
Never rename or delete individual .polish files from the game directory. That will only trigger more sound bank errors. Always let the verification tool handle missing files. If all else fails, a complete reinstallation of