This chapter will delve into accessibility concerns for media materials, including images, video, and audio. Media materials should always be accompanied by alternative descriptions that render this content accessible to people with vision or hearing problems. It merits noting that alternative descriptions don’t just support people with disabilities; they also prove useful in many different scenarios like the following:
- A student uses captions to watch a video for class because she can’t hear the dialogue while working in a noisy environment
- An immigrant to the U.S. uses captions to follow the dialogue in a video
- A person with a slow or unreliable Internet connection reads the alt text for images that she cannot load in her web browser
Common alternative descriptions include: captions, audio descriptions, transcripts, and alternative text (alt text). Captions convey in textual form the sounds and speech interactions in a piece of media. While open captions are permanently placed on videos, closed captions can be turned on and off by users depending on their preferences. According to the Described and Captioned Media Program (DCMP) of the National Association of the Deaf, captions should be:
- Synchronized to appear at approximately the same time as the audio
- Equivalent and equal in content to that of the audio, including speaker identification and sound effects
- Accessible and readily available to those who want or need them
Note the use of subtitles in this Frozen movie trailer with little speech.
Audio descriptions may also be included in videos to narrate what is happening visually on the screen. For instance, listen to this sample audio description provided by WebAIM to show how a Universal Studios logo might be described.
And here again is the Frozen movie trailer—this time with audio descriptions.
Transcripts should also accompany videos to assist those who may not be able to see or hear. As W3C explains in “Making Audio and Video Media Accessible,” transcripts should contain both the speech in a particular piece of media and a description of non-verbal and visual elements that provide useful context.
Alternative text or alt text is usually included with an image, table, or graphic that describes the image in the context in which it appears. As WebAIM explains in “Context is Everything,” alt text will vary depending on the information the author would like to convey with a particular image. Rather than describing everything about an image, alt text should include information that the author is relying on the image to convey. For instance, a picture of George Washington in a history of colonial hairstyles might point out the first president’s approach to wigs or powders. That same image included in a WebAIM article may simply have the alt text designation “example image” because this is all the authors wanted to communicate with the visual.
As WebAIM further explains, alt text should be:
- Accurate and equivalent: Presents the content and function of the image;
- Succinct: Often contains less than 150 characters;
- Not redundant: Presents only information not included in surrounding text;
- Not verbose: Excludes unnecessary words like “image of.”
For an example of alt text in practice, see this sample recording from a screen reader.
You may find yourself needing to address the accessibility measures outlined above in either a remediation project or in your day-to-day decision-making while managing projects. The following case studies may give you some ideas for creating appropriate workflows, exploring a new technique, or adapting your library’s policies and practices. Note as always that these are only a sampling of the accessibility efforts underway in higher education.