Audio Control
What this means
If a page automatically plays audio for longer than 3 seconds, there must be a way for the person to pause or stop it, or to control its volume independently of their system volume. It's fine to autoplay audio that lasts 3 seconds or less. Past that, you must give control back to the user, either with a visible, keyboard-accessible pause control, or a way to lower the audio's volume separately from the overall system volume. This criterion is not about providing captions or transcripts — that's covered elsewhere. It's specifically about not trapping someone with sound they didn't ask for and can't turn off.
Who it affects
Screen reader users are the group most directly affected. Their screen reader speaks page content out loud through the same audio channel, so autoplaying background music directly competes with and can drown out the speech they depend on to navigate. Because the audio started without their action, they may not know where the pause control is, and hunting for it by ear while their screen reader is being talked over is often impractical. People using speech-recognition software can also be disrupted if unexpected audio interferes with their microphone setup. More broadly, anyone in a quiet environment, anyone with cognitive or attention-related conditions who finds unexpected sound distracting, needs a fast, reliable way to stop it.
Code example
Bad
<!-- Autoplaying audio longer than 3 seconds with no controls at all -->
<!-- Once this starts, a screen reader user has no way to pause or stop it -->
<audio src="welcome-message.mp3" autoplay></audio>Good
<!-- Option A: don't autoplay -- let the user choose to start it -->
<audio src="welcome-message.mp3" controls></audio>
<!-- Option B: autoplay is allowed only because a visible, keyboard-operable
pause control is provided and reachable immediately -->
<audio id="welcome" src="welcome-message.mp3" autoplay></audio>
<button type="button" onclick="document.getElementById('welcome').pause()">
Pause welcome message
</button>How to test it
Load every page of the site at a normal volume and listen for any audio or video that starts playing on its own. If something plays automatically for more than about 3 seconds, use only the keyboard to find and activate a pause or stop control. The page fails this criterion if there is no such control, or if the only way to stop the sound is to change your system volume.