I was playing a Youtube video on Chrome and also playing Minecraft. In game when near a redstone clock which creates a clear loud ticking - for each tick the volume on the Youtube video would lower by about 40% for a half second and then return to normal. This was also delayed by about a half second as if the OS was reacting to the loud tick and reducing the other system volume to compensate (though shouldn't it be the other way around and reduce the loud noise?)