A caption in a book or magazine is text under a picture. Captions are text
located on the picture, and, unlike simple subtitles, they inform the reader of
all sounds--a knock on the door, a scream, a telephone ring.
For watching TV, closed captions are hidden in the video signal and need a
decoder. If a TV set is older than 1993, it needs an external decoder. Analog
sets made starting in 1993 must have the decoder built in. By 2002 all digital
sets were required to to have the decoders. These rules apply to all sets 13
inches and larger and to all sets made for sale in the United
States.
All TV delivery systems must carry closed captioning, including cable and
satellite. There are sometimes problems with lower budget cable systems,
however. By 2002 all programming must be captioned. Spanish language programming
is to be phased in until 2010 when all Spanish programs must be captioned.
Who uses closed captioning?
This seems like a no brainer. We all know that closed captioning is used by
people with hearing disabilities. But the largest group of users are those for
whom English is a second language and it has been found that watching closed
captioned TV improves fluency and comprehension. Studies have shown that closed
captioning has helped children and adults learn to read.
How is it possible to have closed captioning in real time?
You are watching a breaking news story where it is impossible for a script
to be submitted to captioners ahead of time. A specialist called a
stenocaptioner listens and types on a special keyboard which then uses a
computer program to translate and add the captions to the TV signal. These
workers must be highly skilled at dictation and spelling and must type up to
250 words per minute.
Where else might closed captioning be found?
Many DVDs have it, displaying captions that look like subtitles. Radio would
require a separate decoder and text display and, although there have been a
number of experiments, there is nothing available for radio. Sometimes closed
captioning can be found on radio programs simulcast on the Internet.
Occasionally a person with a hearing disability can watch closed captioned
movies along with the general public. There have been various systems tried but
the most popular is Rear Window Captioning System. Viewers are given a special
panel of flat glass or plastic with a goose neck that clamps onto the seat in
front of them. At the rear of the theater is an LED display that shows captions
in mirror images. The glass reflects this back to the viewer but other members
of the audience can't see them.