When you press the Play button ClaroRead or WordRead uses the same speech settings (voice, volume, speed) for all of the text it reads out. Everything will sound the same. You might, however, want to put in pauses, or make some text louder, or lower-pitched, or use a different voice halfway through. ClaroRead lets you use Microsoft’s XML Tags to do this. You can alter which voice is used, put in pauses, change pitch and speed and many other things as ClaroRead speaks. This works for both text read out and text saved to audio files.
Since writing this, Microsoft SAPI 5.2 and later versions have introduced support for the W3C standard Speech Synthesis Markup Language SSML so you may want to use that instead of the Microsoft-specific XML detailed here. The mechanisms to employ SSML (start with a < left-angled bracket) are the same, however.