Try this....Click on the Office Button in the upper left hand corner. Click
on Excel Options. Click Customize. In the "Choose Commands From:" drop down
box you can choose "All Commands". Scroll down to "Speak Cells". Add the
speak cell commands to the Quick Access Toolbar.
FYI: If you go into the windows control panel and go into Sounds, Speech
and Audio Devices, then click on Speech, you can select one of three
different computer voices.