The property play-during specifies the sound to be playing while the content text is being spoken.
The play-during property contains following information:
- value: <uri>, [mix, repeat]?, auto, none or inherit;
- initial: auto;
- applies to: all elements;
- inherited: no;
- percentages: N/A;
- media: aural;
- computed value: absolute URI or as specified.
The value uri specifies the path of the auditory file to be played in the background. The value mix if specified will mix the sound of the element with the sound of its parent and the value repeat, if specified, will repeat the sound if it is too short to fill the duration of the element's content; otherwise it will stop when finished or be clipped if it is too long. If the value auto is set, then the sound of the parent element will continue to play once the element has been rendered; in the contrast to that if the value is set to inherit the sound of the parent will be restarted. And naturally the value none will remove the background sound of the designated element.
CSS mixing property example: