Audio only has a text alternative


Description

This rule checks if audio only elements have a text alternative available.

Applicability

The rule applies to any non-streaming audio element that is:

Note: A play button is an interactive element that when activated, plays the audio.

Expectation

For each test target, the outcome of at least one of the following rules is passed:

Assumptions

There are currently no assumptions

Accessibility Support

There are no major accessibility support issues known for this rule.

Background

Test Cases

Passed

Passed Example 1

Audio with controls and internal transcript

<audio data-rule-target src="../test-assets/moon-audio/moon-speech.mp3" controls></audio>
<p>
	The above audio contains the following speech: We choose to go to the moon in this decade and do the other things, not
	because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our
	energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone,
	and one which we intend to win, and the others, too.
</p>

Passed Example 2

An audio element that describes some of the text on the same page. The text on the page labels the audio as an alternative.

<p>
	A part of a speech by John F. Kennedy: We choose to go to the moon in this decade and do the other things, not because
	they are easy, but because they are hard, because that goal will serve to organize and measure the best of our
	energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone,
	and one which we intend to win, and the others, too.
</p>
<p>
	You can also listen to the audio file below to hear the above part of the speech.
</p>
<audio data-rule-target src="../test-assets/moon-audio/moon-speech.mp3" controls></audio>

Failed

Failed Example 1

Audio with controls and incorrect internal transcript

<audio data-rule-target src="../test-assets/moon-audio/moon-speech.mp3" controls></audio>
<p>
	The above audio contains the following speech: We choose to go to the cheese in this decade and do the other things,
	not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of
	our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to
	postpone, and one which we intend to win, and the others, too.
</p>

Failed Example 2

An audio element that describes some of the text on the same page. The text is not visible on the page.

<p style="display: none;">
	A part of a speech by John F. Kennedy: We choose to go to the moon in this decade and do the other things, not because
	they are easy, but because they are hard, because that goal will serve to organize and measure the best of our
	energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone,
	and one which we intend to win, and the others, too.
</p>
<p>
	You can also listen to the audio file below to hear the above part of the speech.
</p>
<audio data-rule-target src="../test-assets/moon-audio/moon-speech.mp3" controls></audio>

Inapplicable

Inapplicable Example 1

Audio without controls.

<audio src="../test-assets/moon-audio/moon-speech.mp3"></audio>

Inapplicable Example 2

An audio element that describes some of the text on the same page. The text on the page labels the audio as an alternative but the controls are not visible on the page.

<p>
	A part of a speech by John F. Kennedy: We choose to go to the moon in this decade and do the other things, not because
	they are easy, but because they are hard, because that goal will serve to organize and measure the best of our
	energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone,
	and one which we intend to win, and the others, too.
</p>
<p>
	You can also listen to the audio file below to hear the above part of the speech.
</p>
<audio data-rule-target src="../test-assets/moon-audio/moon-speech.mp3" controls style="display: none;"></audio>

Glossary

Included in the accessibility tree

key: included-in-the-accessibility-tree

Elements included in the accessibility tree of platform specific accessibility APIs. Elements in the accessibility tree are exposed to assistive technologies, allowing users to interact with the elements in a way that meet the requirements of the individual user.

The general rules for when elements are included in the accessibility tree are defined in the core accessibility API mappings. For native markup languages, such as HTML and SVG, additional rules for when elements are included in the accessibility tree can be found in the HTML accessibility API mappings (work in progress) and the SVG accessibility API mappings (work in progress).

Note: Users of assistive technologies might still be able to interact with elements that are not included in the accessibility tree. An example of this is a focusable element with an aria-hidden attribute with a value of true. Such an element could still be interacted with using sequential keyboard navigation regardless of the assistive technologies used, even though the element would not be included in the accessibility tree.

Outcome

key: outcome

A conclusion that comes from evaluating an ACT Rule on a test subject or one of its constituent test target. An outcome can be one of the three following types:

  • Inapplicable: No part of the test subject matches the applicability
  • Passed: A test target meets all expectations
  • Failed: A test target does not meet all expectations

Note: A rule has one passed or failed outcome for every test target. When there are no test targets the rule has one inapplicable outcome. This means that each test subject will have one or more outcomes.

Note: Implementers using the EARL10-Schema can express the outcome with the outcome property. In addition to passed, failed and inapplicable, EARL 1.0 also defined an incomplete outcome. While this cannot be the outcome of an ACT Rule when applied in its entirety, it often happens that rules are only partially evaluated. For example, when applicability was automated, but the expectations have to be evaluated manually. Such "interim" results can be expressed with the incomplete outcome.

Visible

key: visible

Content perceivable through sight.

Content is considered visible if making it fully transparent would result in a difference in the pixels rendered for any part of the document that is currently within the viewport or can be brought into the viewport via scrolling.

Content is defined in WCAG.


Changelog

Aug 21, 2019fix: update links to WCAG21 resources (#776)
Aug 21, 2019Editorial changes (#725)
Jul 19, 2019chore: run prettier (#688)
Jul 2, 2019Composite rules: Fix broken links in expectations (#627)
Jul 2, 2019chore: Correct various typos (#640)
May 29, 2019chore: add missing contributors (#572)
May 9, 2019Chore: Adapt site to ACT Rules CR format (#547)
May 7, 2019Template update - audio only has a text alternative (#501)
Apr 29, 2019chore: rename files and update associations (#489)
Apr 16, 2019chore: add unique id to all rules (#478)
Apr 15, 2019chore: WCAG ACT RULES CG Website Update (#437)
Jan 9, 20191.2.1 audio only and video only (#276)

Useful Links


Implementations

Tool NameCreated ByReport
Axe-coreDeque SystemsView Report

Acknowledgements