To use RHVoice with NVDA, first install the main RHVoice addon.
Download the addon), version 1.12.0 .
Then follow one of the language links on this page and download and install a voice addon.
For other Windows programs
You can also use RHVoice with other applications for Windows, e.g. JAWS, if they are compatible with Microsoft Speech API Version 5.
Follow one of the language links on this page and download and install a voice. No additional software is needed: everything is included in the voice installer.
Then open the app and download the voices you want to use.