How do i get rid of this annoying static?

I just bought this phone off ebay. Everything works fine except this annoying static i hear when i am talking. I am going to ask for a refund and send the phone back if it can't be fixed, but i love the phone other than this problem and rather not send it back. I know it is not my network, and after researching it, i'm not the only one having the problem. It is this loud static noise when I am talking to someone. I tried it with someone who was sitting in the same room as me, and no static. It sounds sorta like the static i got when i had a loose wire in the speakers in my car. I am just curious if there is a way i can fix it.