You missed 'em.  And you can bring up the list of same when NVDA is running with NVDA+N,H,Q, which opens up the Commands Quick Reference.

Open that and search for the section entitled, 

Synth settings ring

You've got to be on the speech rate setting, but if you are, and don't hop off of it you can use the Increment/Decrement keystrokes to Increase/Decrease the rate.

--

Brian - Windows 10 Pro, 64-Bit, Version 1909, Build 18363  

Science has become just another voice in the room; it has lost its platform.  Now, you simply declare your own truth.

      ~ Dr. Paul A. Offit, in New York Times article, How Anti-Vaccine Sentiment Took Hold in the United States, September 23, 2019