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.