How to edit custom vocabulary for Voice Control (Siri) in Catalina?

[mainemini]

I'd like to add a large number of words used in my work to Voice Control. However, the UI in the Accessibility preference panel only allows entering one word at a time. In Catalina, I believe Voice Control with US English uses Siri's voice recognition.

I can't find the dictionary or other file that is used by Voice Control or Siri. Where is that and how can I edit it to add a large professional vocabulary?

 

[meneush]

Or in Big Sur. Really need this, need to add loads of medical vocabulary which Siri / Mac fails.