The company Ambient has demonstrated a motorized wheelchair that is controlled by subvocal speech. The individual thinks of a particular word and a sensor collar around the user's neck detects the electrical signals sent from his or her brain to the larynx muscles. The computer then matches those signal patterns to pre-programmed "words" used to control whatever apparatus the system is attached to, in this case a wheelchair. The approach is similar to the subvocal speech system recently demonstrated by NASA for future spacesuit communication devices. Engineers Michael Callahan and Thomas Coleman developed the Ambient technology at the University of Illinois at Urbana-Champaign. From New Scientist:
Callahan and Coleman say (the output from the device) can also be sent to a speech synthesiser, allowing a paralysed person to "speak" out loud. Recent refinements to the algorithms used may make it possible to interpret whole sentences thought out by the user. This could potentially restore near-normal speech to people who have not spoken for years, the researchers say.