Section 402 of the ADA is an amendment of the Communications Act of 1934 and specifically requires captioning of all public service announcements. Any television public service announcement that is produced or funded in whole or in part by any agency of Federal Government shall include closed captioning of the verbal content. As stated by the National Center for Law and Deafness, the appropriate auxiliary aid or service depends on the need of the individual. Many people lose their hearing later in life and do not understand sign language. Therefore, captions or realtime translations represent the only medium which is accessible to all deaf and hard of hearing people.
Open captions are the visible subtitles that appear on a TV screen, or video taped production.
Closed captions are subtitles that can only be seen if the television is equipped with a decoder. The decoder is a device that translates codes from a video signal to readable text and outputs the information on the television screen. It must be plugged into the television set and, when active, will transmit captions. Until recently, deaf people had to buy this extra piece of equipment separately. However, since July of 1993, deaf and hearing-impaired people no longer need to buy a decoder.