Audio-only as a media alternative for text


Description

This rule checks audio is a media alternative for text on the page.

Applicability

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

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

Expectation 1

The auditory information of each test target is available as text (directly or via text alternatives) that is visible and included in the accessibility tree.

Expectation 2

Each target element is labelled as an audio alternative for text on the page.

Expectation 3

The label (from expectation 2) is visible and included in the accessibility tree

Note: The term label does not refer to the label element.

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

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

Failed

Failed Example 1

An audio element that describes some of the text on the same page. The audio contains more information than the text does.

<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.
</p>
<p>
	You can also listen to the audio file below to hear the above part of the speech.
</p>
<audio src="../test-assets/moon-audio/moon-speech.mp3" controls></audio>

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

Failed Example 3

An audio element that describes some of the text on the same page. The text on the page does not label 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>
<audio src="../test-assets/moon-audio/moon-speech.mp3" controls></audio>

Failed Example 4

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 label is 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 style="display: none;">
	You can also listen to the audio file below to hear the above part of the speech.
</p>
<audio src="../test-assets/moon-audio/moon-speech.mp3" controls></audio>

Inapplicable

Inapplicable Example 1

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 src="../test-assets/moon-audio/moon-speech.mp3" controls style="display: none;"></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 there are no controls.

<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 src="../test-assets/moon-audio/moon-speech.mp3"></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)
Jul 19, 2019chore: run prettier (#688)
May 9, 2019Chore: Adapt site to ACT Rules CR format (#547)
May 7, 2019Template update - Audio-only as a media alternative for text (#499)
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)
Feb 1, 2019tweak language of media as alternative for text rules (#357)
Jan 22, 2019rule: SC 1.2.3 & 1.2.5 Video alternatives (#204)
Jan 9, 20191.2.1 audio only and video only (#276)
Nov 12, 2018chore: remove selector `data-rule-target` (#347)
Oct 29, 2018chore: change references to included in accessibility tree (#322)
Oct 12, 2018"Included in accessibility tree" instead of "exposed to assistive technologies" (#269)
Oct 9, 2018Fix: testcase generation (#296)
Aug 30, 2018Chore: Update test cases format and descriptions (#230)
Aug 9, 2018chore: rules table & yml front matter (#209)
Aug 8, 2018SC1.2.1-Audio-captions (#159)

Useful Links



Acknowledgements