question regarding voices


Hi, I notice that there is vocalizer from code factory and from nuance an was curious what the difference was between the 2? Are they the same thing? 
Also, is there somewhere I can hear what the elequance voices sounf like?
Lastely, if one purchases a licens for vocalizer, does that license work forever with updates to future versions of NVDA?
Sorry if these are dumb questions, but I could not find info on this...
Thank you 

Join to automatically receive all group messages.