Youtube problems playing video duplicate sound/ads over the top of music video?

In the last few weeks everytime I try to watch a youtube video on my laptop as soon as the page loads you can hear an advertisement after which it plays the video without you having actually pressed play. If you press play on the video you either have two audio's of it or one audio and advertising. I can't find a video box on the page for advert and nowhere does it say 'turn advert off'.

What's going on and how do I stop it please?
Asked Aug 14, 2014

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