Selecting Voices
Press ALT+G or click on the Settings Menu.
Press P (Speech Settings) to open the Speech Settings Properties page.
When the Properties page opens the Voice Selection combo box is active. Use
your UP or DOWN ARROW keys to select the voice you want to modify.
Your choices are:
Reading Voice - the voice used to read and edit text.
Menu Voice - the voice used to read menus and dialogs.
Emphasis Voice - the voice used to read text that is bold, underlined and in
italics.
Press TAB to move to the Voice Name combo box. Use your UP or DOWN ARROW keys to make your selection.
The next four controls are combo boxes that adjust the voice rate, volume, pitch, Use your UP and DOWN ARROW keys to make your selections Press the TAB key to move to the next control.
To test the different voices options, press ALT+T. To stop the test, press ALT+T again.
Before you close this dialog you may want to globally apply your voice setting changes for one voice to the other voices. Press the TAB key until you hear “Apply Settings to All Voices check box,” then press the SPACEBAR to check this box.
Last, if you want to make more setting changes, press ALT+A or TAB to the Apply button and press the SPACEBAR. Exit this properties page by pressing ENTER.

To save the settings permanently:
Go to Settings (ALT-G), then you will be at "Save the Settings". Press ENTER, then ENTER 2 more times to overwrite the default settings file. Open Book will then keep any settings you have changed.