Sound problem in Metal Gear Solid 4

Hello, i've been having this pesky problem with MGS4 for a while now. The problem is that the sound only plays on specific screens such as pressing the X button at the very beginning and those commercials that you see when you start a new game. But there is no sound on the title screen and gameplay. Is there a fix for this awful problem

The framerate is fine for the most part but the lack of sound is the problem.