Understanding WCAG 2.0

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Audio Control:
Understanding SC 1.4.2

1.4.2 Audio Control: If any audio on a Web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume which can be set to be a different level from the system volume level . (Level A)

Note: Since any content that does not meet this Success Criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other Success Criteria or not) must meet this Success Criterion. See Conformance Requirement 5: Non-Interference.

Intent of this Success Criterion

Individuals who use screen reading software can find it hard to understand the speech output if there is other audio playing at the same time. This difficulty is exacerbated when the screen reader's speech output is software based (as most are today) and is controlled via the same volume control as the sound. Therefore, it is important that the user be able to turn off the background sound. Note: Having control of the volume includes being able to reduce its volume to zero.

Specific Benefits of Success Criterion 1.4.2:

  • Individuals who use screen reading technologies can hear the screen reader without other sounds playing. This is especially important for those who are hard of hearing and for those whose screen readers use the system volume (so they cannot turn sound down and screen reader up).

  • This Success Criterion also benefits people who have difficulty focusing on visual content (including text) when audio is playing.

Examples of Success Criterion 1.4.2

Techniques and Failures for Success Criterion 1.4.2 - Audio Control

Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this Success Criterion. The techniques listed only satisfy the Success Criterion if all of the WCAG 2.0 conformance requirements have been met.

Sufficient Techniques

  1. G60: Playing a sound that turns off automatically within three seconds

  2. Playing sounds only on user request (future link)

  3. Providing a control near the top of the Web page that turns off sounds that play automatically (future link)

  4. Providing a user interface control to pause or stop synchronized media (future link)

Additional Techniques (Advisory) for 1.4.2

Although not required for conformance, the following additional techniques should be considered in order to make content more accessible. Not all techniques can be used or would be effective in all situations.

Failures for SC 1.4.2

The following are common mistakes that are considered failures of Success Criterion 1.4.2 by the WCAG Working Group.

Key Terms


process or technique for achieving a result

Note 1: The mechanism may be explicitly provided in the content, or may be relied on to be provided by either the platform or by user agents, including assistive technologies.

Note 2: The mechanism must meet all Success Criteria for the conformance level claimed.