Dell XPS 630i Sound Problem

Hi everone, new to the forum so if im doing anything wrong please let me know. Randomly one day my pc sound started acting up. I would either be watching a YouTube video or playing a FPS game when the sound would... change. I can still hear what im supposed to hear but it just sounds so weird, I dont know how to describe it, kind of static and higher pitched. Well i found a temporary fix which is to plug something in one of the headphone jacks and take it back out and it would fix it self for a while. I have headphones plugged into the back of the XPS in the sound card, ive tried to find out what it is but have no idea (through windows, havent opened the case). It isnt the sound card because when i plug my headphones in the front 3.5 jack it still does the same thing. I use the back port for my headphones and then my front port for when i want to use my 5.1 system. To fix the problem like i said above, i stick the 5.1 systems jack in the front and take it out again. To fix it when i want to use my 5.1 system i just take the jack out and put it back in. Can anyone help me with this problem. A
Also when trying to record my gameplay (COD through theatre) the noise will come up randomly while im recording but when i go to watch what i recorded it sounds normal so could this be something to do with my actual jacks?