Closed captioning

Closed captioning symbol

Closed captioning (CC) is the process of displaying text on a television, video screen, or other visual display to provide additional or interpretive information. Closed captions are typically used as a transcription of the audio portion of a program as it occurs, either verbatim or in edited form.

History

Closed captioning was first developed in the early 1970s to assist the deaf and hard of hearing in understanding television programs. The first use of closed captioning on television was in 1972, and by 1980, the National Captioning Institute (NCI) was established to promote and provide captioning services.

Technology

Closed captioning can be encoded in various ways, including line 21 of the NTSC video signal, CEA-708 for ATSC digital television, and EIA-608 for analog television. Modern digital television systems use more advanced methods to embed captions, allowing for multiple languages and more complex formatting.

Types of Closed Captioning

There are several types of closed captioning:

• Real-time captioning: This is used for live broadcasts and is created by a stenographer or voice recognition software.
• Offline captioning: This is used for pre-recorded programs and is created by a captioner who listens to the audio and types out the captions.
• Pop-on captions: These appear in blocks of text and are used for pre-recorded programs.
• Roll-up captions: These scroll up from the bottom of the screen and are often used for live broadcasts.

Legal Requirements

In many countries, closed captioning is mandated by law for certain types of programming. In the United States, the Americans with Disabilities Act (ADA) and the Telecommunications Act of 1996 require closed captioning for most television programs. The Federal Communications Commission (FCC) enforces these regulations.

Benefits

Closed captioning provides numerous benefits, including:

• Assisting the deaf and hard of hearing in understanding audio content.
• Helping non-native speakers improve their language skills.
• Allowing viewers to follow along in noisy environments.
• Enhancing comprehension for viewers with learning disabilities.

Related Pages

• Subtitles
• Television
• Deaf culture
• Americans with Disabilities Act
• Federal Communications Commission
• National Captioning Institute

See Also

• Subtitles
• Television
• Deaf culture
• Americans with Disabilities Act
• Federal Communications Commission
• National Captioning Institute