Silence automatic audio within three seconds
A sound plays when the page loads and stops by itself in three seconds or less. That is the whole of G60, and W3C counts it as sufficient for the audio-control rule at Level A. What makes it appealing is what it saves you. Sound that runs longer needs a control to stop it, and a screen-reader user cannot go and find that control while your audio is talking over their screen reader. Three seconds sidesteps the problem completely, because the sound is gone before anybody needs to escape it. A fanfare, a spoken tagline, a short instruction, all fine. The moment it runs longer, you owe either a stop control near the top of the page or the choice of not playing until somebody asks.
How we find it in an audit
We load each audited page with the volume up and time anything that starts on its own. Three seconds is the line, and it is a stopwatch question rather than a matter of judgment. Where sound runs longer, we go looking for the control that stops it and note how far down the page it sits, because a mute button below the fold is a control most people never reach. Background video with an audio track gets the same treatment, since a hero video is the usual reason a page starts talking.
How affected users experience it
Two voices at once is not two things to listen to, it is neither of them. When a page starts talking, a screen-reader user cannot hear their own screen reader, which is the one tool that would have found them the button that stops the page talking. That circle is why the rule exists. Three seconds breaks the circle by ending before it can close. Readers with attention and processing disabilities get a smaller version of the same relief.
Passes vs. fails
Passes
A two-second notification chime plays, or better still, nothing plays until the visitor presses Play.
Fails
A brand anthem autoplays for 40 seconds, and the mute button sits at the bottom of the page.
How this gets tested
The W3C publishes test rules that define what a checker looks for here.
- Audio or video element avoids automatically playing audioA tool can check this
- Audio or video element that plays automatically has a control mechanismA tool can check this
- Audio or video element that plays automatically has no audio that lasts more than 3 secondsA tool can check this
Other ways to satisfy this rule
5 guides on this site are filed under 1.4.2 Audio Control. W3C lists this one as sufficient for that rule on its own. Implement it correctly, in a way your readers' software actually supports, and the rule is met.
This guide is our interpretation of W3C technique G60: Playing a sound that turns off automatically within three seconds. W3C publishes its techniques as guidance rather than as the standard, and says so on every one of them. The success criterion is what conformance is measured against, and a technique is one documented way to meet it.