Here is how they put it:
When we launched Voice Search more than two years ago, we wanted it to “just work” right out of the box, without an initial setup process. And so, we built speech models broad enough to accommodate a wide variety of people, regardless of gender, age, and accents, or variations in pitch, pace, and other factors. But we always knew we could build a more accurate model by listening to your voice, and learning how you -- as a unique individual -- speak. So today we’re launching personalized recognition.
If you opt into personalized recognition, we begin to associate the recordings of the words that you ask us to recognize with your Google account. We then automatically use these words to build a speech model specifically for you. This speech model enables us to deliver greater recognition accuracy. Although subtle, accuracy improvements begin fairly quickly and will build over time.
The first time you use Voice Search, you’ll be presented with a dialog to turn on personalized recognition. Google takes your privacy seriously, so you can enable or disable personalized recognition at any time through the Google voice recognition settings on your phone. If you’d like to disassociate your voice recordings from your Google Account, you can do so through the Google Dashboard in the Speech section.
The personalized recognition functionality is currently available for English in the United States. We plan to support other countries and languages in the near future. To enable it, you must have Android 2.2 or higher, and download the latest version of the Voice Search app from Android Market. The new app also includes some improvements to name recognition and speed, especially over 3G and EDGE connections.
So go ahead and download the latest Voice Search app, and let’s get personal!