Apple - How to to specify pronunciations for OS X Lion?
Open Applications > Services > VoiceOver Utility and go to Speech > Pronunciation. Add a subsitution for "Tony" and tell it to pronounce it as "toe nee".
Interestingly, my computer running 10.7.3 with the Alex voice pronounces Tony correctly. Because of this, I wasn't able to test this solution, so it may not work.
You can also use [[inpt PHON]]
:
[[inpt PHON]]_t1OW ~n2EY.[[inpt TEXT]]
See the Speech Synthesis Programming Guide.
If you download the Auxiliary Tools for Xcode package from https://developer.apple.com/downloads, you can use the Repeat After Me application to convert text to the phonetic syntax: