Intel created Stephen Hawking Speech Software ACAT (assistive context-aware toolkit) one time. Generally it’s a system which makes computers more accessible for people with disabilities, but we mostly know it for the unmatched computer-generated sound of Stephen Hawking’s voice.
Now you can download this software for free and to do anything you want with it!
Or you can improve ACAT if you have any ideas. The current version of the software uses visual cues in the user’s face to understand commands. For example, it tracks the movements of professor Hawking’s cheek muscle.
The free version of the software works with Windows XP or later versions. No OS X or Linux, sorry. Also you will need a webcam for tracking.