The Speech Manager extension can be found as a part of System 7.5. If you don't have the Speech Manager extension in your System Folder, and you have System 7.5, search your system disks or CD for it and copy it to your Extensions folder. Metrowerks has also included a copy of this extension in the System Extensions folder found in the Apple Development Products folder of the MW CodeWarrior CD.
If you experience any problems with speech on your Mac, add the following to lines of code after any call to either of the two Toolbox Speak functions: SpeakString() or SpeakText(). Chapter 4 provides the details of the SpeechBusy() function.
If you don't like what's being said in any of the Chapter 4 programs, you can of course change the text that's spoken. Whether the text is in the code or in a STR# resource, just make the change and recompile.