I am using headphones on my Windows 7 computer. This problem has never happened before and it is super annoying. Do not know one thing that be a cause. I tried switching browsers and that didn’t work either. Please help!
What about you speaker volume? Try turning down the computer speakers volume output (accessible from volume menu on the taskbar) and increasing the volume on your headphones instead.
you might also check out following thread on Yahoo Answers, http://uk.answers.yahoo.com/question/index?qid=20100915061437AAT7me5
Try watching video from some other source and see if the problem continues. If so, you might be experiencing interference from your computer that is messing up your audio. This particularly likely if you are using the front headphone jack.
Solution? Uh, well, I don't think there really is one. The problem is interference messing with the cord sending audio from your sound card/onboard sound (at the rear of the computer) to the front jack. You'll just have to plug your cord into your computer's rear sound port.
I assume you're watching streaming videos through your browser. It's probably a nasty advertisement / banner on one of the websites you have open. You might wanna try blocking ads. Please tell us which browser you are using so we can give further advice.