I remember when voice recognition was barely usable (90-00's) then all of a sudden within the last decade voice recognition started showing up and it was amazingly good. Siri can understand most of what I speak to it even while driving with music in the background.

What are the successful algorithms that made this leap forward possible ? HMM's ? Neural networks ? more data/compute ? What changed since Dragon NaturallySpeaking in 1997? Can anyone recommend overview papers/blogs on this topic I could use to get up to speed ?