For people with reading and writing difficulties, having text reinforced by hearing it read aloud can be very useful. Specialised programs have existed to do this for a long time, and in many cases are extremely helpful and highly appropriate and should be seriously considered, perhaps in consultation with professional advice where necessary.
WordTalk is a free text-to-speech plugin developed for use with all versions of Microsoft Word (from Word 97 up to Word 2010). It will speak the text of the document and will highlight it as it goes. It contains a talking dictionary to help decide which word spelling is most appropriate.