I'm working with a page on my site (editing it, refreshing it often) and I've had two Adsense video ads display that have auto-start audio enabled. One was for Disney, the other Clorox.
Sometimes I loose track of where my cursor is while I'm working, so I though possibly I had "hovered over" the ads. But to figure out what ad was playing I had to scroll up several screen widths to find it, so I don't see how anything I was doing triggered it.
Isn't this new for Adsense, the auto-start audio? Have I overlooked an "opt out" setting somewhere?