The current implementation uses aria-label to override the default screen reader behavior of reading aloud the text contents: https://github.com/elastic/eui/blob/master/src/components/table/table_header_cell.js#L61

This presents two problems:

• It means that providing a node as children will cause the screen reader to read something like "Sort [Object object] ascending".
• As the user traverses the cells in the table body, the screen reader reads aloud the associated column header to help the user orient themselves. This means the user hears "Sort {column title} ascending/descending" for each cell they navigate to, which is confusing to hear.

I think one solution would be to use the sortIcon to provide screen-reader-specific sort information. Instead of conditionally rendering it, we could always render it but wrap it in EuiScreenReaderOnly when the column isn't being sorted on. We could then put aria-label={Click to sort ascending/descending} on the sort icon, which will be read aloud after the column text content is read.