A trained captioner cues a pre-prepared script in time to the actors' words. This model works well so long as the actors stick to the script! Often in live performance however, actors improvise and ad lib.
Speech to Text Reporters (STTRs) and Electronic Notetakers (ENTs) are trained to subtitle live, UNSCRIPTED speech in real-time at events. They are, however, rarely trained as theatre captioners. Traditional models of theatre captioning therefore are unable to respond well to the often improvised nature of performance.
The result is that theatre captioners are usually constrained to cueing only the SCRIPTED elements of the show, even when the actor(s) have veered wildly off script, as if often the case with productions like pantos.
Recent developments in theatre captioning technology have made it easier for captioners to output text to a range of different devices. Depending on the size of the venue, one type of output may be more suitable than another (photos 5 and 6).
Sometimes projections are beamed onto the back wall of the stage as part of the set. Three or more lines of text can be integrated with the projections, with the lines scaled towards the top, middle or bottom of the slides.