The need for accessible communications encompasses all information technology. One very important area of focus must be on accessible multimedia, audio and video.
When we provide publicly available content through videos we must ensure equal opportunity for success to individuals with disabilities.
Individuals who are deaf or hard of hearing must have access the audio portions of multimedia and audio only products. This can be accomplished by using captioned video resources—by purchasing captioned video resources whenever possible and by working with Disability Access Services to provide captioning on uncaptioned video resources. Common types of videos that should be captioned include, but are not limited to: videos from internet resources, video sharing websites (e.g., YouTube), DVDs, and video cassettes.
Similarly, individuals who are blind or low-vision might not be able to fully participate in video-only products unless alternatives are provided. Alternatives such as audio descriptions of the video content or transcripts that can be accessed using screen reader software are appropriate in certain circumstances.
WCAG 2.0 states:
1.2.1 Audio-only and Video-only (Prerecorded): For prerecorded audio-only and prerecorded video-only media, the following are true, except when the audio or video is a media alternative for text and is clearly labeled as such: (Level A)
- Prerecorded Audio-only: An alternative for time-based media is provided that presents equivalent information for prerecorded audio-only content.
- Prerecorded Video-only: Either an alternative for time-based media or an audio track is provided that presents equivalent information for prerecorded video-only content.
1.2.2 Captions (Prerecorded): Captions are provided for all prerecorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labeled as such. (Level A)
1.2.3 Audio Description or Media Alternative (Prerecorded): An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media, except when the media is a media alternative for text and is clearly labeled as such. (Level A)
1.2.4 Captions (Live): Captions are provided for all live audio content in synchronized media. (Level AA)
1.2.5 Audio Description (Prerecorded): Audio description is provided for all prerecorded video content in synchronized media. (Level AA)
Audio Content Accessibility
To ensure the accessibility of your audio-only content, you must:
- Provide a transcript for all audio content in an accessible format.
- Users with audio processing disabilities need the audio content to be provided in an accessible format. Developers should provide transcripts for the audio content.
- When a user encounters audio content in any format, a transcript of the content must be available either as a supplemental document or by a hyperlink in the online content to a transcript.
Video Content Accessibility
To ensure the accessibility of your video-only content, you must do one of the following:
- Provide an audio track that describes the video, for example, if the video included a step-by step diagram of a chemical process, the audio track should describe that process.
- Provide a textual description of the video within the content of a website before the video is shown or provide a link to another web page that describes the video.
Multimedia Content Accessibility
To ensure the accessibility of your multimedia (video plus audio) content, you must:
- For any time-based multimedia presentation, a synchronized equivalent alternative presentation must be provided.
- Time-based multimedia presentations come in many forms such as video, audio or animation. These formats must include captions and possibly descriptions of the content if the captions alone do not suffice to describe the content of the video. Learn more about audio descriptions.
- Multimedia content in any format should be checked to see if the captions are in sync with the available multimedia.
Controlling the Content
- Users must be provided methods to control any automated content, i.e. provide controls to start, stop or disable the content.
- Screen readers do not handle animations very well, they monitor screen events. Any animation will be considered a new event and the screen reader will try to interpret the information causing confusion and equipment disruption. Developers should provide methods to start, stop, pause or bypass the content.
- Check if users can control the multimedia content by starting, stopping, pausing or bypassing the content.
- Provide appropriate text based labels for all the controls.
- Screen readers and audio browsers can read the text in the controls if they are created from system fonts and not bitmaps. Providing labels is recommended for both sighted and visually impaired users as an enhancement to the usability of the content.
- Check if all controls have appropriate text based labels.
- Changes in state of the control should be reflected in the label.
- The state of controls in any multimedia application might change. For example, the speaker icon is used by many applications to show that the application is not muted, and a cross on this icon is used to indicate that the application is muted. Unless the label associated with the control changes, the user might be misled by static labels for the control.
- Check if labels change with changes in the control presentation.
- Provide context and orientation information for automated or highly complex content.
- It is possible to attach a text equivalent to multimedia content such as Flash describing the design of the movie and its major components. The description should introduce and explain both the purpose of the screen, its layout, keyboard shortcuts and names of the important labels. This assists the user in understanding the content and its context.
- Verify that the content has an appropriate description.
- Make the tab order logical and consistent with the navigational or visual presentation order of the content.
- Screen readers and audio browsers read from left to right and top to bottom in a line by line format. Users navigate the screen content using a combination of tab and arrow keys. Users expect a logical tab order and to have related elements grouped together in a sequential manner.
- Navigate the content using the tab and arrow keys to verify the consistency and logical order of the content.
Resources & Tools
- Disability Access Services
- The OSU office of Disability Access Services has captioning resources for the campus, and will gladly caption videos for you. They maintain faculty information on captioned media and have an online form to request captioned videos.
- National Center for Accessible Media (NCAM)
- The National Center for Accessible Media is a growing collection of resources for developers and users interested in ways to make rich media accessible to people with disabilities.
- MAGPie is a free tool available through NCAM to help in the creation of captions and audio descriptions for multimedia.
- WebAIM Captioning
- An article from Web Accessibility in Mind (WebAIM) over-viewing captioning on websites.
- YouTube Captioning
- An article from YouTube discussing how to add captions and transcripts to your videos on their site.
- World Caption free software for Macs
- This University of Wisconsin provided free software helps those with Macs caption videos for free.
- SyncriMedia for Macs
- This software, available for purchase, helps those with Macs caption videos.
- DIY Captioning Techniques
- This Ohio State University resource provides lengthy information on how to caption videos yourself.