Cue-before

The CSS   property allows an author to add distinguishing characteristics to semantic elements. This property specifically references a sound to be played before the element has been aurally rendered. If loading of a URL fails, nothing should be played, but if the system does not have the ability to play it, the spec says the system should try to use some sort of cue (audio, visual or other).

Values
HTML example:

TEXT

CSS example:

strong { cue-before:url(orchestralsneeze.wav); }