Each chapter into separeted file

How can I read text in a speech synthesizer so that each chapter reads into one file? Normally, the text is in font size 10 and each chapter begins with bold letters of font size 14 and the chapters are not numbered.

The IVONA Reader program can read each chapter into a separate file, but only if the chapters are numbered, but even if they were numbered, this program is not suitable because it saves any text to a file and leaves out random single words or breaks off entire sentences. The Balabolka program also lacked such an option. Is it possible in Microsoft Word to set each word written in a larger font to have its own numbering, so that there are numbers before the capital word. The first word with a larger font size should be numbered as 1 when the next word appears in a larger font, there is the number 2 before this word and so on?