Captions are on-screen text descriptions (words or symbols) that display a video product's dialogue, identify speakers, and describe other relevant sounds that are otherwise inaccessible to people who are deaf or hard of hearing.
Captions can be either open or closed. Open captions are always in view on the screen and cannot be turned off whereas closed captions can be used as needed and turned on and off by the viewer.
According to the National Center for Health Statistics of the U.S. Department of Health and Human Services, approximately 34 million Americans have a significant hearing loss; of these almost 6 million are profoundly deaf.
Approximately 1 of every 1,000 infants is born deaf while 6 of every 1,000 are born with some level of hearing loss.
In the Telecommunications Act of 1996 television captioning was made mandatory.
Log on to: captioninfo.org for more details.