Using Captivate's Text to Speech feature allows you to quickly convert written text to voiceover audio. It's an awesome feature. However, we recently had a client who felt that Paul (that was the Speech Agent we used for the project) spoke too fast. The client wanted to know if we cloud slow him down a bit.
While you might think that controlling the cadence used by the Speech Agent was beyond your control, it's actually really easy. Prior to converting a slide note to speech, just add a bit of code (known as Voice Text Markup Language or VTML) to the text.
Click the Text to Speech button and regenerate the audio (the existing audio will be replaced with the new audio file). You'll find that the agent's speed has been cut in half (thanks to the 50 you added as part of the VTML code). You can experiment with the speed values until you find a speed that works best for you and/or your client.