1.4.2 - Audio control
If any audio content plays automatically for more than three seconds, give people a way to stop it.
Summary
When audio plays automatically on a page, it should last for less than three seconds or there must be a easy way to pause/stop it.
Requirements
- Audio content does not start playing automatically, or stops after 3 seconds or less;
- Audio that plays automatically and lasts for more than three seconds, can be easily paused and/or stopped.
Why?
- This ensures that people who listen to content with a screen reader can do so without it being drowned out by the audio.
- Unexpected audio may also distress users with cognitive or sensory sensitivity.
Official wording in the Web Content Accessibility Guidelines
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 independently from the overall system volume level. (Level A)
See the W3C's detailed explanation of this guideline with techniques and examples.
Guidance for Design
Ideally
- Avoid audio or video content that plays automatically
If you need to play audio or video content automatically
- Make sure that it lasts less than 3 seconds
If you can't do any of the above
- Provide a keyboard accessible and clearly-labelled 'Pause' button (e.g. 'Pause video') at the very beginning of the page/screen.
More guidance for Design
- Providing a control near the beginning of the Web page that turns off sounds that play automatically technique in the Web Content Accessibility Guidelines