Which of the following is NOT a function of the bell board?

The bell board is primarily designed to manage specific audio functions in a theatrical production, such as playing sound effects, enhancing audio effects, and managing sound transitions. These tasks are integral to the sound design in performances, allowing for a seamless auditory experience that complements the action on stage.

Controlling lighting, on the other hand, falls under the responsibilities of a different system, typically a lighting board or console. This equipment is dedicated to managing the visual aspects of production, such as light cues and intensity, which are crucial for setting the mood and directional focus in a performance.

Thus, identifying the bell board's main functions helps clarify its specialized role in sound management, distinguishing it from the lighting equipment that handles visual effects.