Haha I usually have multiple browsers and tabs running at the same time, since I always test code…..I kept hearing this loud music show up every once in a while and I could not figure out where it was coming from! Just as I got done reading your post I realize it was the video autoplaying from your site! That was hilarious……Now I know what you mean!
To fix it, just go into your Slide editor and look for Global Settings Tab and you should see the option to turn it off.