Perceivable / 1.4 Distinguishable

1.4.7Low or No Background Audio

Level AAA

For prerecorded audio that is primarily speech -- excluding CAPTCHAs, sound logos, or musical expression -- ensure there is no background sound, that it can be turned off, or that it is at least 20dB quieter than the speech. A 20dB gap means the background is roughly a quarter as loud as the foreground.

Note

A detailed commentary for this success criterion is not yet available. In the meantime, this page lists related patterns, techniques, and links to the normative sources.

Related Techniques

Specific implementation techniques for meeting this success criterion. This site doesn't include the full text, so follow the links to the original W3C documents.

Normative References