Captions are broadcast in one of two ways:
- Where a program can be accessed ahead of broadcast, captions pre-prepared. They will typically appear as blocks of text and have been timed to match the program dialogue.
- For ‘live’ programs such as news, current affairs and sport, there is no time to prepare caption files ahead of broadcast so a captioner is listening to the audio at the same time as the viewer with the captions created by either stenography or respeaking and going to air in real time.
Because the captioner does not know what’s going to be said in advance, and because of further very brief delays inherent in the broadcast chain, a delay of 3-7 seconds between the words being spoken or stenoed and the captions appearing on screen is generally unavoidable.