Welcome to Adobe Captivate forums,
Yes, This is possible by defining custom pronunciations for words which need a change in phonetics. This can be done by defining these pronunications in the "User Dictionary" and the steps are illustrated in this blog post : http://blogs.adobe.com/captivate/2009/07/text-to-speech_-_user_dictiona.html
The post refers to Captivate 4 but the info is valid for Captivate 5 as well and you need not perform step 5 mentioned in the above blog.
Try it out and let us know if this is what you wanted.
Ashwin Bharghav B
Adobe Captivate Team
1 person found this helpful
If all you want is for the TTS voices to spell out the words but for the CC text to contain the words as they would normally appear on a page you can just have a duplicate line where ever such a word would appear in your Slide Notes. There are tick boxes on each slide note line for TTS or CC. If the CC text is exactly like the TTS voice then just tick both boxes. Where you need the TTS voice to spell out the word one letter at a time, copy the text from the line, and have one version in TTS and the other as it needs to be in CC.
Many thanks to you both! I actually used both of your answers in my final solution, modifying the CC text for the previously created projects, but updating the pronunciation for future projects.
I really appreciate your help!