Video chat can be an empowering tool for hard-of-hearing internet citizens for whom sign language is easier than voice. Most chat software doesn't easily bring an interpreter into the equation, however, which spurred Google into adding a Sign Language Interpreter app for Google+ Hangouts. The web component lets chatters invite an interpreter that stays in the background while they verbalize hand gestures. Google is also helping reduce dependencies on the mouse for those who can't (or just won't) use one during chat: there's now keyboard shortcuts to start or stop chats, disable the camera and other basics that would normally demand a click. Both the interpreter app and shortcuts are available today.
Source:Anna Cavender (Google+)