Sam Blackburn: The voice behind Stephen Hawking at 70

Sam Blackburn has been Hawking’s technician since 2006. And for these 5 years, he’s the one responsible for the technology that has allowed Hawking to communicate through a computer and a voice synthesizer by twitching his cheek.

When he was diagnosed with motor neurone disease (or ALS) at 21, physicist Stephen Hawking was only expected to live a few years. He turns 70 this week.

Since about 1986, he’s had to use a menu controlled by a computer system to speak. A computer highlights cells in a big grid of letters or words, and when the correct one is highlighted, he presses a switch.

But when he became unable to move his hands sufficiently, he moved to an infrared system mounted on his glasses, which detects movement in his cheek muscle. His facial muscles are the only ones he can control reasonably well.

When Blackburn first started, the system was breaking all the time. “I’d get calls at 1 o’clock in the morning saying ‘Stephen can’t speak, what do we do?’” he says. “So I needed to modernize the system.”

He did so incrementally, so the learning wouldn’t be too steep. “Stephen wouldn’t be able to ask for help because the very thing he wouldn’t be able to use would be the speech system,” he says. “Understandably that has made him very reluctant to upgrade.”

The only copy of Hawking’s hardware voice synthesizer is contained in a little gray box in Blackburn’s office. The card inside dates back to the 80s, and this particular one contains Hawking’s voice. There’s a processor on it that has a unique program that turns text into speech that sounds like Hawking’s, and they have only two of these cards.

The company that made them went bankrupt and nobody knows how it works any more. Blackburn is trying to reverse engineer it since they can’t just update the system with a new synthesizer.

“The voice is one of the unique things that defines Stephen in my opinion,” he explains. “He could easily change to a voice that was clearer, perhaps more soothing to listen to – less robotic sounding – but it wouldn’t be Stephen’s voice any more.”

However, Hawking’s progressive nerve decay means that his ability to control his cheek muscle is fading.

His rate of speech is down to about one word per minute. And while Blackburn’s been making slight advances in the current technology, they’re gonna have to move on to something new – like eye-tracking or brain scanning systems.

The challenge for Blackburn’s successor: to keep that well-known voice in working order.