Definition of Closed Caption and Conventional Subtitle

Indira Ahmed Fernandez | Jan. 2022
Bachelor of Hispanic Letters

History

The optional subtitling system emerged in the United States in the 1970s, with the aim of transmitting additional information through television. The response of the deaf community to this phenomenon was very enthusiastic and its use gradually spread to all visual media. Although its use is not massive or absolute, its importance has led to its presence in almost all media, including mobile applications. In several countries it is mandatory to include the decoder that allows its transmission in the design of the televisions.

Unlike conventional subtitles, Closed Caption aims to go beyond the linguistic, as they express audio elements and events that occur beyond the dialogue. These elements can often be overlooked in the perception of people with soft spot auditory, since they are audio emissions that sometimes occur outside the visual shot.

For example: The camera focuses on two people having a conversation, but the background noise indicates that someone broke a window in the nearby space. This event is not captured on the screen and will be indicated by the sound of breaking glass, in addition to the body reaction of the protagonists of the story. scene.

Functioning

The optional subtitle for the deaf or hard of hearing is sent through line 21 of the frames in NTSC systems, analog television. In digital television, it is more common Format universal version of SMPTE-334-1, capable of adopting DTVCC (Digital Television Closed Caption) as well as other electronic data systems in VANC (by vertical auxiliary packages) with respect to SDI signals and HD-SDI.

One of the most interesting aspects of the transmission of this system is that when a dialogue occurs, the parliament is located in screen below the person saying it in question, this way there will be less confusion as to who is involved and in what moment. Despite the existence of a universal form, each region has its codes, with which the community will identify itself.

There are two ways to do it. They can be used as well for live broadcasts as they are for recorded broadcasts. In the second case, it is simpler, since all the information is transcribed, which is ready and recorded for the moment in which you want to see the content. Conventional subtitles also work this way.

In live broadcasts the matter is a bit complicated, since some voice recognition system is used, on which the text produced and transmitted. The weak point of these programs is machine learning, since it is essential to create voice models for each interpreter, who must repeat texts aloud seeking a better understanding of the machine's intonation or speech features. This will mean that, in the simultaneous dictation for live transmission, fewer errors are generated and the information can be received in an optimal way.

other functions

Although the main function of Closed Caption is to bring most of the audiovisual information to deaf or hard of hearing people, other benefits have been highlighted in the application of this system.

This modality is also applied in very noisy environments (such as airports) or in places where silence must be kept (such as certain hospital wings). This ensures the complete reception of the information that is intended to be transmitted.

Likewise, it is successfully used in the learning of foreign languages ​​(or in this case the language of the video), since you have the text and the pronunciation in the same package. In this sense, it is also important to keep in mind that it will help to understand certain idioms or you speak of specific places, since it will generally be lexicographically adapted to the mode of the country or region where it is employ.

Bibliography

Audiovisual arts commission: On Closed Caption and audio description.

Santa, R.: What you should know about Closed Caption.