One of the most prevalent qualms users have of Google Voice is its occasionally accurate interpretations of what's being said. However, with the upcoming public debut of the Project Fi cellular service, Google has reportedly greatly improved its transcription service. According to a post on the company's blog, Google's managed to reduce its transcription error rates by nearly 50 percent by leveraging a "long short-term memory deep recurrent neural network." Users do not even have to change their routine to take advantage of the new system, just keep using Voice and Fi as they always have.
Via : http://www.engadget.com/2015/07/24/google-voice-transcriptions-will-soon-actually-make-sense/