faint static when using earphones or headphones on macbook air 13

Just recently discovered my Macbook Air 13 inch (which I've had for nearly a year now) has this faint static sound when I'm using earphones or headphones (tested many different kinds and it still has static) and it just hums continuously when listening to music and anything with sound, i was looking through other forums and people had similar problems but never encountered anyone having issues with a macbook air. its really frustrating, is there a way to fix it?