Audio problem: Joker's TV debut as an opera singer isn't very convincing. Even through the partially-obscuring clown mask, you can see that his lips aren't moving at all. (00:22:30)
Arthur, the Invisible Bear - S2-E4
Audio problem: When the station wagon pulls into the mountain clearing there is no movement with the trees indicating they are on a sound studio, as some of the dialogue is acoustic. (00:24:00 - 00:24:30)