General

Could also be a power issue too, I remember my laptop use to do this annoying popping sound/click while I have my headphones on, fixed it using a power filter from monster. Not really ideal since it's expensive but my area has weird power fluctuation due to heavy construction at the time it happened.

Edit: Actually, I remember I could hear the clicking from the power brick itself too, if you are playing on a laptop and it has a brick, you may want to see if you hear some clicking from that too.

Not at all