Headphone jack issues

Question

Whenever I bump the plug attached to my headphones, I lose audio quality. I have had this issue with more than just this mp3 player; two cd players and a tape player have also experienced this problem. Since it is so common, someone must know how to fix it. I have tried cleaning out the jack (I thought that maybe there was some dust or something blocking the connection) but it did no good. Has anyone ever managed to fix this problem?Any assistance would be appreciated.