Closed captioning is a system that presents the dialogue and sound effects of television programs and prerecorded movies as text on a television screen. It thus enables viewers who are deaf or hard of hearing to better enjoy television broadcasts and movies. It also serves as an educational tool for people learning English as a second language. Closed captioning came into use in 1980 in the United States and in 1981 in Canada. In the 1990’s, closed captioning became part of the standard equipment in televisions.
Closed-captioning information is stored in a portion of the TV signal that does not make up part of the ordinary picture and sound. For prerecorded television programs and stand-alone media, such as Blu-ray discs, captions are typed into a computer and encoded (added to the programming) before broadcast. Live broadcasts, which are shown as they happen, are typically captioned by a skilled typist called a stenocaptioner typing on a shorthand machine. A computer translates the shorthand and encodes the captions.
Two major laws affect captioning in the United States. The Television Decoder Circuitry Act of 1990 requires most television sets made after July 1993 to have the ability to display captions. The Telecommunications Act of 1996 required broadcasters to add captions to an increasing number of programs. By 2008, all programming was captioned in English. By 2012, all programming was also captioned in Spanish. Since the early 1990’s, the Canadian Radio-television and Telecommunications Commission has required Canadian broadcasters to increase their use of closed captioning. In Australia, the Australian Communications and Media Authority has done the same.
In the first decade of the 2000’s, commuters began using the closed-captioning feature on their smartphones, laptop computers, and tablet computers to watch television programs or films on their devices without disturbing their fellow travelers.
