How to fix sound distortion on an iPod?

I have a 4th generation iPod shuffle. When i use ear buds with it, the sound will be fine at first, but after a few days the sound will start to get distorted. If I mess with the ear buds for a little I can fix the sound for a few seconds. After a while the ear buds will stop working with the iPod all together. If I buy a new pair of ear buds the whole thing starts all over again. The ear buds work fine on my PC regardless of how well they work on my iPod and when I restore my iPod it's work fine for few minutes. Any suggestions?