Introduction to Media
Media is any non-text content inserted into a web page. The way to make a non-text content accessible, is by using text alternatives.
Provide text alternatives for any non-text content, like an image, audio or video, so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.
If the non-text content serves only decorative purposes, then a text-alternative is not necessary.
If the content is in audio or video format, an extra file must be created that tells the same story and presents the same information.
Images
When an image contains words that are important to understanding the content, the alternative text should include those words. This will allow the alternative text to play the same function on the page as the image.
Text alternative does not necessarily describe the visual characteristics of the image itself, but must convey the same meaning as the image.
How to Add Alternative Text
This is done through the same interface that allows you to upload the image. In the image options look for a field called “Alternative Text” or “Alternate Text” or sometimes just “Alt Text”.
The “Title” and “Description” fields are not used for accessibility purposes.
In Wordpress, the alternative text field is next to the label “Alternate Text”.
Guidelines for Alternative Text
- Ensure that the text alternatives communicate the purpose of the graphic accurately and succinctly.
- Do not provide text alternative for graphics which do not convey content.
- Do not repeat the alternative text of an image in the adjacent text.
Alternative text is meant to be relatively short (up to 260 characters), so it would be an abuse to write more than a few words, or, at most, a few short sentences.
Long Description
Complex images, such as charts and graphs, may be too complex to describe in a brief alternative text. The answer then, is to provide a brief description of the image as an alternative text and then provide a long description elsewhere.
Elsewhere, may be near the image, like right below.
Here is an example of a long description, right below a chart.
The percentages of total U.S. non-institutionalized population age 16-64 declaring one or more disabilities are:
- Total declaring one or more disabilities: 18.6%
- Sensory (visual and hearing): 2.3%
- Physical: 6.2%
- Mental: 3.8%
- Self-care: 1.8%
- Difficulty going outside the home: 6.4%
- Employment disability: 11.9%
Source: WebAIM
By putting the long description within the document where the graphic occurs, you are serving everybody, not just those with disabilities.
Audio
Provide an accessible alternative way of presenting the information in an audio presentation. Create a document that tells the same story and presents the same information as the prerecorded audio content.
The document serves as long description for the content and includes all of the important dialogue and as well as descriptions of background sounds etc. that are part of the story.
Captions provide the part of the content available via the audio track.
Better to refer to an expert on how to make accessible audio content.
You may also want to check Soundcloud. It offers an easy to use interface for creating audio content and adding captions through its comments.
Video
Video content is inaccessible to people who are blind and to some who have low vision. Therefore, it is important for them to have an audio alternative.
One way of doing this is to provide an audio track describing the information in the video. The audio should be a common audio format used on the internet, such as MP3.
Better to refer to an expert on how to make accessible video content.
You may also want to check Youtube. It offers an easy to use interface for adding captions to your video.
