The Google Now voice assistant on Android phones may work offline soon. A team of engineers from Google recently published a paper, demonstrating 
how they had used voice commands on a smartphone, with a 13.5% error rate, on a Nexus 5 with 2GB of RAM and 2.2 GHz processor. The paper demonstrates a lightweight speech-recognition program being run on a smartphone. Speech recognition programs like Google Now, Siri and Cortana all depend on cloud based systems right now. Interestingly, Google Now’s error rate, using the cloud-based system, is at around 8%.
If speech recognition is available for offline use, it would enable companies to make the feature faster on smartphones, since the voice data will not have to be sent back to Google’s servers. In addition, it may also be more power efficient and should enable new features for smartphones. That said, being offline, it would presumably mean that the various Search-based enquiries will not be available. You can read the entire paper published by the engineers, here.
Google has been making big progress in artificial intelligence and machine learning recently. DeepMind Technologies, a UK-based Google-owned company, recently demonstrated the power of its AlphaGo AI, by beating world champion Lee Seedol in one-on-one competition.
