Richness

The   property is used in CSS with audio sounds. This property specifies the richness, or brightness, of the speaking voice. Higher values of richness/brightness have rougher waveforms and tend to carry better than lower richness values with smoother waveforms ("smooth" as in when the waves are drawn, not heard). Before its inclusion in CSS2, this property was first proposed in the W3C Working Draft "Aural Cascading Style Sheets (ACSS)" (1/7/97, http://www.w3.org/Style/CSS/Speech/NOTE-ACSS).

Values
CSS example: