Captioning is a transcription from spoken language into written language on the screen of all kinds ranging from television and cinema to laptop used in classroom. It may be transcripted in advance or in live time.
You probably have already noticed a closed captioning in a waiting room in a clinic or in a pub. Thanks to Deaf advocates for making it happen. Today, many hearing people enjoy captioning while watching sports or another show in a loud bar. Many immigrants enjoy learning English by listening and watching the captions. It's one of some wonderful contributions made by Deaf advocates (Deaf Gain).
You may see a symbol "CC" and another symbol that looks like a "Q" on the back of a DVD at a movie rental store. It indicates that this DVD movie has a closed captioning.
All television sets in the U.S. produced after 1990 have a caption-decoding chip. If you live in North America, you most likely have a captioning feature in your television set. If you want to see, pick up your remote control and find a setting to turn the CC on.
Not all TV shows or programs are closed-captioned, but today in the United States and Canada, by law, all programs must have one.
While captioning is an accessibility for deaf people, there are some advantages about captioning for everyone: reading/listening in a loud setting (e.g. pub) or quiet place (e.g. library, waiting room, etc.), English/other-language learners, etc.
Source: unknown. Perhaps another side of this "problem" is rather also a benefit -- knowing when it's safe to watch again with the clue of the unemotional captions.
CART is a realtime captioning or transcribing in some settings such as a classroom, courtroom, and meeting room for some deaf and hard-of-hearing students and participants.
Rear Window Captioning is a small portable mirror screen that a deaf or hard-of-hearing person uses in a cinema. The flag-like device is placed inside the cup holder of any seat and the person adjusts the screen to fit her/his view. The deaf person sits and watches a movie while the portable screen shows captions.