Rocket Validator integrates axe-core version 4.1,
which currently checks 91 accessibility rules, into an automated web site scanner.
Accessibility rules tagged as WCAG: 1.4.2.
Ensures <video> or <audio> elements do not autoplay audio for more than three seconds without a control mechanism to stop or mute the audio.
People who are blind or have low vision and use screen reading software can find it hard to hear the screen reader's speech output if there is other audio playing at the same time. If automatically playing audio lasts more than three seconds, an easily located, accessible mechanism must be provided to pause or stop the audio or control the audio volume. An audio control allows screen reader users to hear the screen reader without other sounds playing.
Playing audio automatically when landing on a page may affect a screen reader user's ability to find the mechanism to stop it because they navigate by listening and automatically started sounds might interfere with that navigation. Therefore, we discourage the practice of automatically starting sounds (especially if they last more than three seconds), and encourage that the sound be started by an action initiated by the user after they reach the page, rather than requiring that the sound be stopped by an action of the user after they land on the page.