This property specifies whether the text will be rendered aurally and if so, in what manner. The possible values are −
- none − Suppresses aural rendering so that the element requires no time to render.
- normal − Uses language-dependent pronunciation rules for rendering an element and its children.
- spell-out − Spells the text one letter at a time.
Note the difference between an element whose 'volume' property has a value of 'silent' and an element whose 'speak' property has the value 'none'. The former takes up the same time as if it had been spoken, including any pause before and after the element, but no sound is generated. The latter requires no time and is not rendered.