speak-header | NN n/a IE n/a CSS 2
| Inherited: Yes
For text-to-speech-capable browsers, this specifies whether the browser calls out the name of a table cell's header prior to the cell's value every time that value is read aloud or just one time for all adjacently read cells that share the same header (e.g., navigating downward through a table column).
CSS Syntax
    speak-header: headerFrequency
Value
Two possible constant values: once | always.
Initial Value
once
Applies To
th elements.