DTV Access
The Basics
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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.
The most common method of broadcasting video description uses the Separate Audio Program (SAP) feature of stereo television. This allows blind and visually impaired viewers the option of selecting the described track through the flip of a switch or the touch of a remote control button. NCAM is working now to ensure description tracks will be on of the many audio tracks available on digital broadcasts.
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?
Currently, you can find descriptions on select PBS programming on 169 Public Television Stations, reaching over 80% of US television households. Select movies have also described for The Turner Classic Movie Network including the DVS Showcase offered every Sunday evening at 6:00pm (ET). The DVS Showcase has offered classics such as "Casablanca" and "North by Northwest".
Through WGBH's Motion Picture Access Project (MoPix), many films have been captioned and described for first-run and specialty theaters. Click here for more information on the MoPix project. Home Video - DVS sells described videos through a direct mail catalogue that offers more than 200 titles including new and classic feature films and public television titles.
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.
