Google on Tuesday switched on a new program that will dramatically improve the accuracy of its speech recognition service, which allows people to use verbal commands to search the Internet, send an e-mail or post a Facebook update.

Users of the latest Android-powered smart phones can now allow Google to recognize the unique pattern of their speech by downloading a new app from the Android Market. The service gradually learns the patterns of a person’s speech and eventually will more accurately understand their voice commands.

Google’s plans to allow your computer or smart phone to speak back to you, in a “voice” that will sound increasingly natural, and even human.

The linguistic models that Cohen’s team has helped develop over the past six years at Google, based on more than 230 billion searches typed into google.com and speech inflections recorded from millions of people who used voice search, are now so vast and complex that it would literally take several centuries for a single PC to create Google’s digital model of spoken English.