Hawking was 21 when he was diagnosed Lou Gehrig's disease, an incurable degenerative disorder that has left him almost completely paralyzed. While an infrared sensor attached to his glasses translates the pulses in his right cheek into words spoken by a voice synthesizer, the nerves in his face have deteriorated and those close to him say his rate of speech has slowed to about a word a minute.

"This is a research project," Rattner told The Associated Press, saying the team's task was to gather data for further study.

Finding ways to keep Hawking communicating has long been a challenge. Lou Gehrig's disease, also known as amyotrophic lateral sclerosis, attacks the cells that control muscles — leading to weakness, slurred speech and paralysis.

Hawking managed to overcome his deteriorating speech for a while by dictating scientific papers to a secretary, or speaking through an interpreter. He lost his voice entirely after a tracheotomy in 1985, and a computer was built to synthesize his speech in a distinctive, robotic monotone that has since become almost as famous as the scientist himself.

At first, Hawking retained some limited hand movement and could manage about 15 words a minute. Now that even the nerves in Hawking's cheek are beginning to fade, Rattner argued it was time for a new approach saying that solutions based on brainwaves or eye tracking were among the technologies being considered.

But Rattner said his best bet was on high definition cameras that pick up on the minute movements in Hawking's face to synthesize his speech. "My wager is some form of facial feature recognition will unlock it for Stephen," he said.

The Santa Clara, California-based company has long provided Hawking with many of his technological needs  including an upgrade of his speech software and the connection that links his wheelchair-mounted computer to the Internet.