To access spoken information about a form, users with vision impairment need to use a screen reader. Screen readers speak information about where the cursor is located on the form. As the form author, you must specify the text for the screen reader to read. If the form will be saved in PDF you must also generate a tagged PDF form.
LiveCycle Designer ES supports the Microsoft Active Accessibility (MSAA) compliant screen reader, JAWS for Windows from Freedom Scientific.
See also 

Support for screen readers