Optimal Design of Broadcast Teletext Caption Preparation Systems

The provision of television captions for the benefit of the hearing impaired is the growing practice of many broadcasting organisations. This paper discusses the research and design work which led to the development of ´NEWFOR´, a caption preparation system for broadcast teletext. Caption preparation is a complex and time-consuming task, which often required as long as 30-40 hours preparation time per captioned programme hour using early teletext origination systems. Research carried out into the display requirements for captioning for the hearing impaired led to a design specification for a stand alone caption preparation system and a handbook of guidelines on captioning. Analysis of the operational requirements of caption preparation provided a framework for optimal task division between the human captioner and the captioning computer. The system developed as a result halves caption preparation time, and also permits captioning of live programmes. The system described is now available commercially and is used for all teletext captioning by Independent Television in the UK.