Update _rules/audio-transcript-2eb176.md

Co-authored-by: Kathy Eng <kengdoj@users.noreply.github.com>

Author: HelenBurge

_rules/audio-transcript-2eb176.md

@@ -28,7 +28,7 @@ acknowledgments:
 This rule applies to every [non-streaming](#non-streaming-media-element) `audio` element for which at least one of the following is true:
 
 - the element has an `autoplay` [attribute value][] of `true`; or
-- the element has a [play button][] that is [visible][].
+- the element has a [play button][] that is [visible][] and [included in the accessibility tree][].
 
 ## Expectation