Audio descriptions are an additional audio track that describes what is on the screen, designed to meet the needs of visually impaired users. To better understand audio descriptions, you might find it helpful to know that they’re sometimes called descriptive video. Audio description tracks fill in information that may be missing in the standard audio track, but is displayed to viewers visually. These should be available in a form that can be used with and alongside the video, rather than separately from it.
A Sample Audio Description
Imagine a video for a history course on 17th century Holland; the screen shows the image of a painting by Vermeer. The standard audio track may offer information relating to the painting, but doesn’t provide a student who cannot see the screen any information about exactly what is on the screen. In this case, the audio track might say, “Aged oil painting of a young woman, with a scarf over her hair, near a window. She is wearing a pearl earring.” Now, the user who cannot see the painting has an idea or point of reference for additional content in the video.
Using Audio Descriptions
Audio description tracks enable the user to toggle between two audio stream; one is the standard audio for the video, while the other is the additional audio description. There are several different ways to make use of audio descriptions in video content.
- Video creators can opt to include audio descriptions in their main soundtrack. While this can be challenging, it saves any need for an additional track. For instance, an instructor might say, “the screen shows a PowerPoint slide detailing…”.
- Audio description tracks can simply be uploaded as a secondary track. This track can include only the essential audio to fill in information the student requires.
- An audio description track that includes the full lecture content can also be produced and made available as an alternate track.
YuJa’s HTML5 Media Player supports the use of an audio description file, available through the individual file Accessibility settings.