Described video

What are Described Videos?

Described videos are videos described by a second audio track (Audio Description) produced along with the original audio track. The second audio track provides descriptions of important visual elements of a film or television show. Description was initially created to improve access to videos for individuals with low vision or blindness, but also can be beneficial for individuals who learn better when key visual information is verbalized or highlighted.

Generally, descriptions should be factual observations and not include subjective interpretations. Descriptions are designed to provide an audio account of images on the screen that is relevant to the overall plot or topic. Some examples of described information include body language and facial expressions, costumes, unspoken movements, and changes in the background.

Types of Described Video

Live Description

Live Description is description of a live video that is created as the video is being aired. Examples of live description would be news clips or media coverage of an ongoing event. As these descriptions are being created in the moment, they are less scripted; however, often listeners may be unable to tell the difference between live description and description that is added after the filming.

Post-production Description

  • Open description: description of a video that has been merged with the program-audio track in a way that the descriptions cannot be turned off by the viewer.
  • Closed description: description of a video that is recorded as a separate track which holds only descriptions and is timed to play at specific spots in the timeline, in parallel with the program-audio track. Closed description can be turned off and on by the viewer.
  • Open and closed descriptions may be created differently but would sound identical to the listener. Quality Education is Accessible by the TheDOITCenter is an example of a regular open or closed description video. The video Audio Described Version: Tortoise vs Turtle is another example – compare it to the non-described Tortoise vs Turtle video. With regular open and closed description, the description is added to the original track without pausing the original track.
  • Extended video description (EVD): extended video description is characterized by creating pauses in the original video and audio to play a longer description that would normally be permitted. The video continues when the description is finished playing. EVD is used when there is insufficient time between separate dialogues and within natural pause in the dialogue. This process extends the timeline of the entire video, and has thus not been possible in broadcast television; however, video recordings and on-demand Internet systems can make this a practical possibility. Extended video descriptions can be open or closed. 
    • Extended video description (EVD) has been reported to be beneficial for individuals with cognitive and developmental disabilities, as descriptions describe what is going on which could help the viewer to look out for things (e.g. characters’ moods, cause and effect relationships) that may be missed out due to other distractions in the video.
    • The video Everybody Technology – Steven Hawking’s Dream – Audio Description Version is an example of an extended video description. Compare it to the non-described video Everybody Technology – Steven Hawking’s Dream and notice the 20-second pause at the beginning of the described version.
  • Text-to-speech tracks: computer-generated text to speech tracks are similar to regular description, but provide text descriptions instead of using a recorded voice. Text descriptions can be sent separately and read by someone using a braille device or a screen reader. This allows the viewer to have more control over the speed of the descriptions but may be difficult to synchronize with the actual video because of the potential variance in reading speed.

Pre-production Description

Embedded Described Videos (EDV) is a new type of accessible media, where the description is built into the script during the production process. Traditionally, the standard process would be to add the described video track after the show has been produced. However, with EDV, the program is accessible the moment it is produced and there is no need to add post-production narration as the narration is added during and as part of the production process itself. This type of description is an example of how media can be created to be more accessible, without appearing to have any alterations or adjustments.  

An example of embedded description can be seen in the video Exploring the Boreal Forest, with Albert Karvonen. As part of the video, notice how the interviewer and the naturalist provide some extra description of what is happening in the video “We’re standing in front of a sign that says …”. The description is incorporated in the dialogue, so does not stand out as being separate information. Overall, the use of embedded description is an example of more inclusively designed video content.

Other Audio Adjustments

Clean Audio is created by isolating spoken dialogue and key non-speech information; this information is then played at an increased volume, while other background sounds or music are played at a lower volume. Clean audio can provide improved accessibility for those who are hard of hearing or have difficulty isolating important auditory information from a video. Although clean audio could be applied to a video on its own, it can also be used to diminish the background noise so that descriptions may be added.

Who can provide described videos?

SNOW does not endorse any of the following companies. These links are provided for information purposes only. These are a handful of many different audio description companies.