I think the discrepancy lies between "open source" and "modern" in this case. It is true that DNNs outperform traditional HMM models, but speech recognition sys

I think the discrepancy lies between "open source" and "modern" in this case. It is true that DNNs outperform traditional HMM models, but speech recognition systems are complex. It's not trivial to simply "port" an existing open source system to switch to DNNs if you don't have the manpower and training data that Google and the like possess.