Understanding 1.4.7 Show Hide techniques and failures for 1.4.7 Sufficient Advisory Failures Sufficient Techniques for Success Criterion 1.4.7 Note: Other techniques may also be sufficient if they meet the success criterion. See Understanding Techniques. G56: Mixing audio files so that non-speech sounds are at least 20 decibels lower than the speech audio content Back to top 1.4.8 Visual Presentation Level AAA For the visual presentation of blocks of text, a mechanism is available to achieve the following: Foreground and background colors can be selected by the user. Width is no more than 80 characters or glyphs (40 if CJK). Text is not justified (aligned to both the left and the right margins).