Described video (DV) is also referred to as audio description (AD) and even descriptive video. All three mean the same thing but the terminology changes depending on where you live. Audio description is more commonly used in the USA, UK and Australia while described video is the preferred term in Canada.
AD (DV) is a narrated description of a program’s main visual elements, such as settings, costumes, or body language. The description is added during pauses in dialogue and enables people to form a mental picture of the program. For broadcast, AD (DV) is carried on secondary audio tracks. It can be enabled in your cable box audio settings. For web, audio description (described video) is either enabled as a secondary audio track within the media player or is presented as ‘Open AD’, meaning the AD (DV) is part of the main soundtrack.
This is a very common question. If the visuals in your video only support what is being spoken, then likely you will not need to include audio description (described video). However, if there are relevant visuals which are not mentioned in the video’s main soundtrack, then descriptions are needed to be WCAG (Web Content Accessibility Guidelines) compliant.
If your video contains key visuals not mentioned in the soundtrack but there is little to no pauses in the dialogue/narration, consider either Extended Audio Description or a Descriptive Transcript.
A descriptive transcript (audio description transcript) is a text document that contains a transcript of all spoken words along with descriptions of key visual elements and sounds that are needed to provide context.
The DV transcript allows the blind and low vision audience access to your video by using their screen readers.
Extended AD (DV) is a technique used to provide descriptions when adequate pauses in dialogue are not available. With Extended AD, the video is paused at critical points to allow the describer time to accurately describe pertinent visual elements.
Extended AD is often a preferred method for corporate and educational videos where words are spoken over visual elements.
The short answer is no. At this time, YouTube does not support a secondary audio track for audio description. However, it appears that the feature is in the works. We will provide an update once the information is made available. In the meantime, what you can do is upload a second version of your video which includes audio descriptions in the mix. (Remember to label this version as ‘audio-described’ or ‘described video’ within the title).