Principle 1 Perceivable · Guideline 1.4: Distinguishable
1.4.2 Audio Control
Sound that starts automatically and runs longer than three seconds must be stoppable.
What this means in practice
Auto-playing audio drowns out a screen reader and makes the page unusable. Better not to autoplay at all – otherwise provide a pause control near the top of the page.
Normative wording
The binding text lives at the W3C. What you read here is our own faithful rendering – not a quotation.