In the '80s after Stephen Hawking lost his ability to speak, he began looking into text-to-speech options. It was at MIT that Hawking met American Dennis Klatt, who was also working with computer-generated speech algorithms. Klatt lent his voice to one of the first programs that changed text into speech. It was called the DECtalk, and the company that made Hawking's first computer incorporated Klatt's voice.
Hawking would continue to use Klatt's voice as his own for many years. In fact, the filmmakers for The Theory of Everything had to get Hawking's permission to use the likeness in the movie. Over the years, Hawking had been offered an upgrade on the voice but he always declined, preferring to keep Klatt's original.
When speaking with the Queen of England, who asked if Hawking still had that American voice, Hawking quipped:
Yes, it is copyrighted actually.
Klatt, a member of MIT's Speech Communication Group, passed away in 1989, just a year after Hawking began using his voice. He was committed to assisting those with disabilities using his knowledge of computational linguistics.
Thank you, Mr. Klatt, for giving a voice to one of the greatest minds of our time.
Thank you Intel for doing all what you could have to get the treasure of information to us. THANK YOU— Arunesh Narayan (@narayanarunesh) March 14, 2018
Bravo Intel , This is the best thing you have done ,giving a voice to a genius, a legend.— Livio (@livio_macaj) March 14, 2018
He once said ''It would not be much of a universe if it wasn't home to the people you love.''...RIP Stephen Hawking😢— Mohammad Hisham (@MohammadHishamX) March 14, 2018
Stephen Hawking's theories unlocked a universe of endless possibilities. He was given only 2 years to live but he ended up being one the most iconic voices on the planet. He will go down in history as a legend of science. Thank you Stephen for what you have taught our world. pic.twitter.com/oyEvEggWj3— SocialSend (@SocialSendCoin) March 14, 2018
Hawking used his voice to appear in many animated shows, recording his own voiceover work.
Hawking also participated in a humorous video for the Paralympics.
I remember watching Stephen Hawking on TV as a little girl. He was the first voice that showed me stars weren’t just something beautiful to admire every night, they were the object of a million questions, as is the whole universe. This loss cuts deep. RIP to a GREAT physicist pic.twitter.com/GYIVYLUjO2— Dianna Cowern (@thephysicsgirl) March 14, 2018