A11ying with Sanna - Web Content Accessibility Guidelines a guide to the accessibility requirements
1 Perceivable

1.4.2 Audio Control

Conformance level: A
Criterion released in WCAG version: 2.0

Official description of the success criterion

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.

What to do?

Provide a mechanism to stop, pause, or control the volume of audio that plays automatically.

Why is it important?

Helps users who have difficulty focusing with background audio.

How to test for it?

Check that there is a mechanism to stop, pause or mute audio that plays automatically for more than 3 seconds.

It's always better for accessibility if audio doesn't play automatically.

More about this criterion elsewhere