Taken from:
http://arstechnica.com/information-technology/2012/05/google-glasses-patent-hints-at-speech-to-text-display-for-deaf-users/

Google is unveiling it's "Google Glasses" project.  This is definitely an interesting project - and potential a 'game-changing' technology (or ... 'disruptive technology').  As you approach somebody and think "Yes - I remember that person - what is his name" - Google glasses have used facial recognition and on the lens printed "John Doe" - so you can say "Hello John" when you get closer to him.  Theoretically it can have more on "John Doe" - "John is a financial officer at XYZ bank, you know him from a graduate class in summer 2008 where he got an "A" and wrote his final paper on RFID chips in bank notes")

The article referenced here goes in another direction - for the hard-of-hearing / deaf individuals - it can identify noises and obstacles that they wouldn't hear - "the phone is ringing" / "bang - crash - there was a car accident just to your right", etc.

The article notes:

Perhaps most interestingly, one patent shows Google is working on a system to help hard-of-hearing and deaf users detect and interpret nearby sounds. The glasses' heads-up display would show arrows and flashing lights to indicate the direction and intensity level of the sound, and even display the words nearby people are speaking. 

So, while the deaf won't quite 'hear', they can 'see sounds' - and that can be a very positive move for them!!!