How can I do this in my book?

There are lots of ways to customize the display of information in Book Builder.

If you choose to record your own voice in the audio recording section, you can choose to speak at the rate you desire...very slowly, very quickly, etc.

To change the SIZE of text, you can do that yourself as an author right in the "Add/Edit Text" window by using different size font. You can also zoom in or out through your browser.

 

You can also play with the COLOR that you decide to use for your text for added emphasis.

Click here to see how one author uses color to customize the display of content in the book, El Jaleo.