DTV Access: A Resource Site for Industry and Consumers
DTV Description FAQ

What is video description?

Video description makes television accessible to people who are blind or visually impaired. Narrated descriptions of a program's key visual elements-such as actions, body language, graphics, and scene changes-are recorded and carefully blended into natural pauses in the program soundtrack, creating an additional mixed audio track broadcast simultaneously with the program.

Descriptions in DTV are treated as an alternate audio selection which is transmitted during the regular broadcast. Viewers can choose the description audio channel from a menu. However, the channel that carries the descriptions is not always identified as such, and may appear in the menu as a secondary audio channel, or as a second channel of English audio, or even a channel of foreign-language audio. NCAM is working to ensure description tracks will be properly identified in future digital broadcasts.

Learn more about video descriptions from the Media Access Group at WGBH.

What is Descriptive Video Service®?

Descriptive Video Service® (DVS®) was developed by WGBH and launched as a permanent, national service on PBS in January 1990. DVS is a registered trademark of WGBH.

Which television programs include DVS?

Descriptions can be found on a variety of television programs on hundreds of PBS stations as well as other network programming, including The Simpsons on Fox, Frontline on PBS and CBS's CSI: Crime Scene Investigation as well as in movies, on DVD, in museums and other attractions and on the Web.

Through WGBH's Motion Picture Access Project (MoPix), many films have been captioned and described for first-run and specialty theaters. Learn more about the MoPix project.

How are descriptions created?

Carefully trained writers (describers) use special computer software to map out the pauses in a program to determine how much room is available for inserting descriptions. The describers then craft the most expressive and effective descriptions possible, taking care to preserve the dramatic integrity of the program. Editors check the script for timing, continuity, accuracy, pronunciation, and flow. Once the script is approved, a professional narrator voices the script scene by scene. The narration track is then merged with the program audio to form the described soundtrack.

What elements of a program are described?

We describe key visual elements in a program that a visually impaired viewer would ordinarily miss. Actions, costumes, gestures and scene changes are just a few of the elements that when described, engage the blind viewer with the story. Our describers are experienced writers and researchers. When they encounter visual images that are unfamiliar to them, they take the time to research and create descriptions that will give the viewer a more complete image of what is transpiring on-screen.