Click on the dropdown arrow next to the Quick Access toolbar and choose More Commands.
In the dropdown, select All Commands.
You should then see a new Speak selected text icon appear on the Quick Access toolbar. When you click it, the word that the cursor is against will be read. To read a chunk of text, highlight the section before you click the button. To read the whole document, press CTRL and A together (the shortcut for select all) before clicking the button.
There are similar options in other Microsoft Office products.