Earlier quoted context omitted.
I agree - I don't care how good Google gets it, this is an unsolved problem until I can do it with open source tools operating without an internet connection.
Google has basically invented a special processor with a very, very, VERY weird architecture for these sorts of tasks: https://drive.google.com/file/d/0Bx4hafXDDq2EMzRNcy1vSUxtcEk... I don't think this level of computational power can be achieved on a modern CPU, or even a GPU! But GPUs are probably the closest analog to Google's absurdly parallel architecture. To get a GPU working at maximum performance, you either…
The issue previously has been a lack of large enough high quality annotated datasets, and open source ASR libraries being a bit behind or not well integrated with cutting edge deep learning. I think that's changing now though. I hope it won't take too long until pre-trained, reasonable size and high accuracy TensorFlow/Kaldi models for many languages are common.