It's a glitch I figured this out for Toon Twister 3-D.
When I click and hold other actors, rollover the actor you chose and release the mouse, you get actor duplicated. I chose Goddard in this video. You see in direct mode, There are duplicated actors. When the sayings/lines or actions are in the timeline, you click on invisible ones and those actions and lines are visible, so now you get the actor's voice duplicated in the same time.