Mine has begun to do the same , I be leave that an apple add on may be the culprit. This applies for both apple and windows. It appears when on you tube, did this with my apple amusing it was all good shortly after the pops and clicks appeared when i began sound tap. went to my windows computer program there all good there, went on you tube and some time after this add on appeared ,did not allow it to install every thing still fine but this add on keeps trying, Not Happening! This problem is on start up. I would look there. Hope you find it and come up with an update.