Losing sound during game play
Because DirectX installs a new set of extensions for the sound drivers sound may be lost. Sound may return after restarting the computer, restarting the game, or never.
Also, make sure your sound card manufacturer does not have a proprietary set of DirectX drivers that may be required to be used for the sound card to properly work. If the manufacturer does not have a proprietary set of drivers, it is recommended that you download the latest version of DirectX.