1.4.2: Audio Control [A]
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 independently from the overall system volume level.
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 or not it is used to meet other success criteria) must meet this success criterion. See Conformance Requirement 5: Non-Interference.
Sufficient Techniques for Success Criterion 1.4.2
Note: Other techniques may also be sufficient if they meet the success criterion. See Understanding Techniques.