Video and audio content can help to make web pages and course curriculum more engaging. However, they can also erect barriers unless delivered with accessibility in mind. When delivering video content, you must consider the following accessibility issues:
- Some people are unable to hear audio. Therefore, audio content such as audio-recorded lectures or podcasts must be accompanied by a transcript, and videos must be provided with closed captions.
- Some people are unable to see video. Therefore, video must be carefully scripted or edited in a way that ensures all important content is accessible through the audio track. If this is not the case, any important information that's presented visually must be described in a separate narration track using a technique called audio description.
- Some people are unable to operate a mouse. Therefore, multimedia content should be delivered in a player that can be operated with keyboard alone, and that has controls that are properly labelled so that they are announced properly to screen reader users, and can be operated effectively by speech input users.
Creating Accessible Videos
Videos should be produced and delivered in ways that ensure that all members of the audience can access their content. An accessible video includes captions, a transcript, and audio description and is delivered in an accessible media player. See below for more details about each of these features. This information was written specifically for people producing or delivering video at the Oregon Department of Education.
Captions are text versions of the audio content, synchronized with the video. They are essential for ensuring your video is accessible to students, employees, and members of the public who are deaf or hard of hearing. They also help non-native English speakers to understand the video, make it possible to search for content within the video, help all students learn the spelling of technical terms spoken in the video, and make it possible to generate an interactive transcript where users can click anywhere in the transcript to watch the video where that text is spoken.
YouTube automatically generates captions for most videos when they're uploaded using speech recognition technology. These machine-generated captions are rarely if ever fully accurate. However, if their accuracy is decent and captions can be perfected with only a few minor corrections, the easiest way to correct them is to do so directly in YouTube.
The end product generated by the second and third options is a caption file. Most caption files are plain text files with time codes indicating the start and stop times. Popular caption file formats include SRT, WebVTT, and TTML, all of which are supported by YouTube.
To add captions to videos on YouTube, you must be the owner of the YouTube account where the video is hosted. The specific steps for uploading your caption file change frequently as the YouTube interface is upgraded. However, the general sequence is fairly consistent.
Audio Description Examples from the Videos
Narrator speaking when a dog barks
Narrator: See Spot run. See Spot sit. See Spot bark (bark bark)
Change of Speaker
The first time spell their names out completely, then you can just use the first letter of their name.
Audio is Bad / Not Understandable
Describe High Pitched Speaking or Eerie Background Music
[high pitched speaking]
#yesterday, all my troubles seemed so far away#
Caps for Increased Volume
use CAPS to RAISE THE VOLUME SHOUT of a word(s) in a sentence
Add three consectutive periods to denote a pause.
talking along and...
A transcript is a text version of the media content. A transcript should capture all the spoken audio, plus on-screen text and descriptions of key visual information that wouldn’t otherwise be accessible without seeing the video. Transcripts make video content accessible to everyone, including people who are unable to view the video due to accessibility problems or technical limitations. They are also helpful for people who want to quickly scan or search a video’s content but do not have the time to watch the entire video.
If you have captioned your video, a transcript is available as one of the optional output formats produced by the closed captioning process. This is true of both the free online tools and the commercial service providers. To make the transcript available simply link to it from your web page, wherever you link to or display the associated video.
Using YouTube with a Screen Reader
Helpful to know about people using screen readers with YouTube.
External WCAG References
Most Details from this page were gleaned from the University of Washington's Accessible Technology section.