Technical question?

Alright, so I'm having this problem with the speakers on my laptop: Whenever I try to play a disk that has audio on it (examples: PC games, CD's, DVD) the speakers make this crackling noise while playing it. It does not do this when I try to play audio files that are already on my computer like music, it only does it when I'm using a disk. Can anybody tell me why this is happening, or better yet a way to fix it?