The rare disease progressively destroys neurons in the brain and spinal chord. These motor cells control the muscles that enable us to move, speak, breathe, and swallow. With no neurons to direct them, muscles gradually weaken and waste away. Symptoms of ALS include muscle weakness and paralysis, as well as impaired speaking, swallowing, and breathing. But intellectual capacity remains intact throughout, in most cases. Life expectancy is generally between two and five years from the onset of symptoms.
Hawking is a rare ALS patient in that he has not succumbed quickly to the disease. That has been a boon to the scientific community. Despite his physical limitations, he has managed to publish dozens of papers, plus numerous popular books, including the best-selling A Brief History of Time (Bantam Books, 1994). "I try to lead as normal a life as possible, and not think about my condition and the limitations it places on me," he told me recently in an interview.
NEW VOICE. Central to Hawking's work and existence is his use of assistive technology. Due to his lack of muscular control, Hawking's speech became so slurred in the 1970s that few people could understand him. He wrote scientific papers by dictating letters to a secretary. He gave seminars through an interpreter. In 1985, Hawking received a tracheotomy to make it easier for him to breathe. But the operation robbed him of any remaining ability to speak.
For a time, he could only communicate by spelling out words letter by letter by raising an eyebrow when a helper pointed to the right letter on a spelling card. As you might imagine, this method of communications was slow, tiring, and frustrating. Hearing of Hawking's plight, Walt Waltosz, the founder of software company Words+ (www.words-plus.com), sent him a copy of his E Z Keys program.
This program, which retails for $1,395, can predict and complete words in sentences, speeding up the ability of people with disabilities such as ALS to communicate. It can also convert text to speech with an integrated synthesizer program on any PC-compatible machine using Windows 95 or higher and a processor running at a minimum of 133 MHz. Hawking runs the program using several fingers in his right hand, where he still retains limited mobility.
OPENING DOORS. The software is much more than a communications tool. The program also functions as an environmental control, allowing Hawking to turn on and off appliances, select his favorite CD to play, or control almost any other device that has an on/off switch. "E Z Keys is absolutely essential. The environmental-control unit allows me to control the doors in my house and office. I also use E Z Keys to produce and edit all of my presentations, papers, and books," says Hawking.
The program's word-prediction database holds up to 5,000 words and allows users to save thousands of set phrases that can be quickly retrieved and vocalized. E Z Keys even allows Hawking to give live lectures, an amazing feat for someone with such an advanced case of ALS. "When I have built up what I want to say, I send it to a speech synthesizer," says Hawking. At first, he just used the program on a desktop PC. But this was cumbersome and slow.
So Hawking got help from David Mason of Cambridge Adaptive Communication. Mason fitted a small portable computer and a speech synthesizer to Hawking's wheel chair. Voila! His writing speed went from under 10 words a minute to 15 words a minute. Hawking can either use the voice synthesizer to speak what he writes or save it to disk. From there, Hawking can print out his thoughts, or call them back from the disc and speak them sentence-by-sentence. Using this method of communication, Hawking has written several books and scores of scientific papers, and has given hundreds of talks.
LOUD AND CLEAR. As a scientist, clarity and quality of speech are vital to Hawking. For that reason, he believes the quality of the speech synthesizer is very important to holding an audience's attention. "One's voice is very important. If you have a slurred voice, people are likely to treat you as mentally deficient," he says. Hawking is amazed at the progress that speech synthesizers have made. "The only trouble is that it gives me an American accent," he jokes.
Had Stephen Hawking lived a century ago, many of his thoughts on the universe would would never have been recorded, and the world would have lost tremendous input from a truly original and great mind. Here's a model example of how assistive technology is contributing mightily to the intellectual capital of the world.
"While I have lost the ability to speak, I have not lost my ability to think. These products were designed specifically for people, like me, who can't speak," says Hawking. Now, the world can hear him loud and clear, as he unlocks the mysteries of the universe thanks to intelligence, perseverance, software, and hardware. Williams writes Assistive Technology every week, only for BW Online.
Got a comment or question? Please visit our Assistive Technology interactive forum