Call of Duty Black Ops: Sound not working, sound fix

Sometimes after launching the campaign mode of Call Of Duty Black Ops, the sound goes out (just after the cinematic). This doesn't happen in multiplayer mode so you might wonder what the problem is. Read on below for the very simple solution.

To resolve the Sound issue on Call of Duty Black Ops:

• You need to update the Microsoft DirectX end-user runtime.
• This link installs a number of runtime libraries from the legacy DirectX SDK for games that use D3DX9, D3DX10, D3DX11, XAudio 2.7, XInput 1.3, XACT and Managed DirectX 1.1
• This link will take you to the relevant Microsoft page: https://www.microsoft.com/en-us/download/details.aspx?id=35