Ad's taking over audio from site videos

Earlier I was watching the Nvidia Shield Tablet review (full screen) when suddenly a loud T-mobile ad started blaring over the audio. I thought I had another tab open but I did not. Eventually I found that the small ad at the bottom of your page had suddenly started playing at loud volume. I just wanted to make you aware as I can't imagine you would want the ad to function this way.

A screenshot or any other additional information that would make pinpointing which ad in the rotation is causing the issue easier would be great, beyond that hopefully it won't take long to get it out of the rotation if it's negatively impacting the user experience like it sounds like it is.