If you are talking about the Cyberon voice dialer, yes they can be backed up. I used to do it all the time. I dont have it installed in this rom right now, so can't remember the exact steps. but i think it was on the voice tab tab in settings, then there was 2 icons at the bottom looked like floppy disc icons sort of. one of them would import, the other export.
if you dont have the export option available, there is an updated patch for it that will enable it. let me know if you need it; i have it here.
edit: upped it to my webhoster. you can use the following link to get it if needed:
Cyberon Voice Speed Dial Patch