How Intel Gave Stephen Hawking a Voice

Mike's Notes

I hope that Pipi CMS can provide an AAC (picture language) interface as one of its accessibility options.

…we have a moral duty to remove the barriers to participation, and to invest sufficient funding and expertise to unlock the vast potential of people with disabilities. - Stephen Hawking

Resources

• https://www.wired.com/2015/01/intel-gave-stephen-hawking-voice/
• https://www.vitrx.co.uk/the-technology-that-allowed-stephen-hawking-to-communicate/
• https://github.com/intel/acat
• https://theconversation.com/the-technology-that-gave-stephen-hawking-a-voice-should-be-accessible-to-all-who-need-it-93418
• https://www.bbc.com/news/technology-33991887

References

• Reference

Repository

• Home > Ajabbi Research > Library > Subject > Accessibility
• Home > Handbook > 

Last Updated

05/02/2026

How Intel Gave Stephen Hawking a Voice

By: João Medeiros

Wired: 13/01/2015

João Medeiros is Features Director for Wired magazine. He was born in Portugal, and came to the UK at eighteen. He has a PhD in theoretical physics at Imperial College. He has written widely for publications including The Economist, GQ and Nature.

Stephen Hawking first met Gordon Moore, the cofounder of Intel, at a conference in 1997. Moore noticed that Hawking’s computer, which he used to communicate, had an AMD processor and asked him if he preferred instead a “real computer” with an Intel micro-processor. Intel has been providing Hawking with customized PCs and technical support since then, replacing his computer every two years.

Stephen Hawking

Wired January 2015, Relates to special feature on Stephen Hawking, Hawking sits in his personalised special electric wheelchair, text in foreground from him screenMarco Grob/WIRED UK

Interview

There is a 17-minute interview behind the paywall.

---

Other Notes

The "Equalizer" is a 1980s computer program developed by Words Plus CEO Walter Woltosz to help his mother-in-law, who had ALS. It enabled Professor Stephen Hawking to communicate by selecting letters, words, and phrases on an Apple II computer via a hand switch, later upgraded to a cheek-switch sensor. 

Key Details of the Equalizer:

• Purpose: Developed to assist patients with ALS who lost the ability to speak and write.
• Usage: Hawking utilized this software, later integrated onto his wheelchair, to produce up to 15 words per minute.
• Operation: The user interface allowed for selecting words from a database or spelling them out, which were then converted to speech using a Speech Plus CallText 5010 synthesizer.
• Development: Walter Woltosz co-founded Words Plus in 1981 and created the software to provide a voice for those with communication disabilities. 

---

Stephen Hawking and the Technology that allowed him to continue his research18/03/2018

Stephen Hawking, who sought to explain the origins of the universe, the mysteries of black holes and the prospect of time travel, died today aged 76. Hawkings body was ravaged by the wasting motor neurone disease (ALS) he developed age 21 and spent most of his life confined to his wheelchair.

Hawking’s incredible mind probed the very limits of human understanding both in the vastness of space and in the sub-molecular world of quantum theory, which he claimed could predict what happens at the beginning and end of time.

In his 2013 memoir “My Brief History” he explained how at first he “felt it was very unfair” and often questioned “why should this happen to me.” With time and technology, he went from concern that his life was over and his potential never realised to now, 50 years later, feeling quietly satisfied with his life and achievements.

How Intel gave Hawking his voice.

In 1986, aged 44, Hawking lost his voice to save his life after an attack of pneumonia. For a while, he used a spelling card to communicate, patiently indicating letters and forming words by raising his eyebrows. Although this gave Hawkings the ability to communicate the process was slow. From then on, he spoke through a computer synthesiser on the arm of his wheelchair.

A chance encounter with Gordon Moore, the co-founder of Intel, at a conference in 1997 led to a relationship that would see Intel providing Hawking with customised PCs and technical support, replacing his computer every 2 years.

Martin King, a physicist who had been working with Hawking on a new communication system, contacted a California-based company called Words Plus, whose computer program Equalizer allowed the user to select words and commands on a computer using a hand clicker. Words Plus CEO Walter Woltosz had created a earlier version of the speech equalizer to her help his mother-in-law who also suffered from ALS.

Equalizer first ran on an Apple II computer linked to a speech synthesizer made by a company called Speech Plus. This system was then adapted by David Mason, the engineer husband of one of Hawking’s nurses, to a portable system that could be mounted on one of the arms of a wheelchair. With this new system, Hawking was able to communicate at a rate of 15 words per minute.

However, the nerve that allowed him to move his thumbs kept degrading. By 2008, Hawking’s hand was too weak to use the clicker. His graduate assistant at the time then devised a switching device called the “cheek switch.” Attached to his glasses, it could detect, via a low infrared beam, when Hawking tensed his cheek muscle. Since then, Hawking has achieved the feat of writing emails, browsing the internet, writing books and speaking using only one muscle. Although this system worked it was still slow… enter SwiftKey. With SwiftKey integrated, the system could learn from Hawking and predict the characters and words he planned to type next based on historical patterns, with this data funnelled through to his speech synthesiser. SwiftKey has also tapped Hawking’s historical works to help it more accurately predict his next words in this bespoke version of the software.

The technology that enabled Stephen Hawking to speak.

As you might expect, it is not just one piece of equipment that is involved here. Many technologies combined to allow Hawking to communicate.

• Lenovo Yoga 260 provided by Lenovo and Intel, Intel® Core™ i7-6600U CPU
• 512GB Solid-State Drive
• Windows 10
• ACAT interface software provided by Intel

Speech Synthesisers (3 copies):

• Manufacturer – Speech Plus (Incorporated 1988, Mountain View, CA)
• Model – CallText 5010
• Speaker and amplifier provided by Sound Research
• Permobil F3 wheelchair provided by Permobil

It is undoubtedly the incredible technology that enabled Hawking to speak again that gave him the hope and drive to continue with his work. Hawking was an Ambassador of Science and showed us what determination looks like.

What happened to Stephen Hawking?

Stephen Hawking died on March 14, 2018, aged 76. In itself, an incredible achievement, but Stephen did much more than simply survive for 76 years. His life was an inspiration to so many people. Interestingly, he didn’t believe in God or the afterlife. He called heaven “a fairy story.”

In his final, posthumous book “Brief Answers to the Big Questions.” he wrote “there is no God”. and “no one directs the universe.” He had disputed the existence of God for many years before his death.

he wrote, “The question is: Is the way the universe began chosen by God for reasons we can’t understand, or was it determined by a law of science? I believe the second,”

Hawking believed that “spontaneous creation” was the reason for existence, writing “it is not necessary to invoke God to light the blue touch paper and set the universe going.”

He will be remembered for many years.