Computer sound problems: scratchy sound?

i have been working with my laptop in the past days because i was so tired of fixing my sound problem which is very distorted and scratchy. I already adjusted the volume and i made it all full volume.Likewise, because there's no progress yet, i adjust the sound effect but still the problem was unsolved. I already check the sound driver but there's no problem all was properly working. My suspect regarding this problem is my sound effect. How to fix this problem? Are there software that i can download to fix this problem? What things i have to make to restore my sound setting? Are there possibilities that i can fix it?