Cutting the grunts made it funny

In one episode, Homer and Smithers get into a fist fight, with Smithers holding an old-fashioned rotary phone, and the animation is harsh as they hit each other back and forth. At the sound mix on a Thursday, it played as a stream of grunts and thuds, horrifying and not funny at all. The show was set to air that Sunday, and the animation could not change.

First the team tried funny sound effects, like boings, and that made it even less funny. Finally, as an experiment, they removed every sound of exertion, the ugh, ugh, ugh, and left only the sounds of pain. That version was funny.