The sound engineer is responsible for ensuring the correct sound balance between the cast and orchestra, as well as between dialogue and singing. They also set up cues and timing for sound effects. The sound engineer needs to be familiar with stage sound systems.
The lighting director works within the director’s vision of the show to create the right atmosphere for each scene through the use of lights – for example, whether the scene is night or day, indoors or outdoors – and sets up cues for lighting changes. They need to be familiar with stage lighting systems and computerised lighting control systems.