Hi Walter,

Those voices do not come with NVDA.  Those are bought as an Add On to NVDA.  I bought them from some place called Code-something.  Sorry, their name starts with the word Code, but I can't remember the rest of their name.

However, I had nothing but problems with their Vocalizer voices for NVDA. 

In Win 10, I started using the Voices that come with Win 10, and I use the one named David, which to my ears is clean and clear enough for my uses. 

I like the Vocalizer voices and use them with JAWS all the time, but just had funky problems using them consistently with NVDA.

Others mileage may vary.

Grumpy Dave