2.1.1179 Part 4 Section 4.6.9, audio (Audio)
For additional notes that apply to this portion of the standard, please see the notes for tnLst, §4.6.87(b).
a. The standard allows the isNarration attribute to be set to true on any audio element.
The isNarration attribute can only be true if the <audio> element contains a child <cMediaNode> (“[ECMA-376] Part 4 §4.6.29; cMediaNode (Common Media Node Properties)”) with a child <tgtEl> (“[ECMA-376] Part 4 §4.6.81; tgtEl (Target Element)”) that contains a <spTgt> element (“[ECMA-376] Part 4 §4.6.72; spTgt (Shape Target)”) that points to a valid sound shape. A valid sound shape is a shape that includes as a child of the <nvPr> element (“[ECMA-376] Part 4 §126.96.36.199; nvPr (Non-Visual Properties)”) one of the following elements: <wavAudioFile> (“[ECMA-376] Part 4 §188.8.131.52; wavAudioFile (Audio from WAV File)”) or <audioFile> (“[ECMA-376] Part 4 §184.108.40.206; audioFile (audio from File)”).