Speak on Enter
One of the most effective ways to use Text to Speech is its Speak on Enter mode. When you click the Speak on Enter button on the Text to Speech toolbar, the Text to Speech feature reads every data entry you make back to you. (The program actually says the words, "Cells will now be spoken on Enter," the moment you click this button.)
When the program is in this speaking mode, the Text to Speech feature speaks every data entry you complete. Note that, in the world of Excel, "complete" in this case means you've either pressed the Enter key or pressed a cursor-movement key such as an arrow key, Tab, or Page Down. The feature does not speak the entry if you complete it by clicking the Enter button on the Formula bar.
Note that the Speak on Enter button is a toggle; you turn off this speaking mode by clicking the button a second time. When you click the button to turn Speak on Enter mode off, Text to Speech says, "Turn off Speak on Enter."