By Louise Fenner
Device for Disabled Converts Brain Signals into Spoken Words
Two young inventors are perfecting a device that gives back the power of speech to people who suffer from diseases or
disabilities that have taken away their ability to talk.
The device, called the Audeo, translates thoughts -- or, more precisely, brain signals sent to the vocal cords -- into
synthesized speech. Using the same technology, inventors Michael Callahan and Thomas Coleman also have created a
mechanized wheelchair that moves, turns and stops in response to intercepted brain signals.
The first commercially available speech device "is slated for the middle of 2008, designed specifically for people with
ALS or diseases that have similar types of effects," Callahan said in an interview from his office in Champaign,
Illinois, where he and Coleman co-founded the Ambient Corporation three years ago to research and market the Audeo. Both
men are now 25.
"If development goes well, it should give them a full vocabulary, their ability to speak," Callahan said.
ALS -- amyotrophic lateral sclerosis, or Lou Gehrig's disease -- can rob people of their physical motor control and
ability to produce speech. So can some other diseases, as well as traumatic brain injury, cerebral palsy, stroke and
certain spinal cord injuries. Callahan and Coleman are anxious to help people with such conditions.
In fact, Callahan said, "our goal is to make [the Audeo] affordable to people who may or may not have health insurance,
because we want the technology to get to everyone -- so it will be priced accordingly."
"The technology is not finished, so the communication we can give them is limited but extremely useful where there are
no other options," he said.
The Audeo uses sensors located in a neckband worn by the user to detect electrical impulses in the vocal cords and relay
them to a nearby computer that converts the signals to speech. But users need not fear that the device can read their
minds, Callahan said.
"It's a step above thinking and a step below actually speaking, so you have to want to say it," he explained. "If you
don't want to say it, we have no signal to detect and nothing is able to be communicated. But if person does actually
want to say it, we're able to capture the instruction signal that your brain sends."
Existing communication devices for severely disabled people generally require them to select a button or word on a
computer screen, or use a head-tracking or eye-tracking system to move a cursor on the screen. Some people are unable to
do even these things, said Callahan, "so we're trying to provide a more efficient way to input thoughts into a
He estimates that some 3 million people in the United States and 60 million people worldwide could benefit from this
technology. "We've gotten a large amount of interest from countries all over the world, from people who have different
diseases and disabilities," Callahan said. "Our first roll-out will be targeted toward English speakers, but we have the
technology to cross the language barrier and to enable people to speak in other languages."
One goal, he said, is to "build a community of people; we want to connect all the people that need these types of
devices, so they can talk with each other."
He and Coleman started investigating the technology as engineering students at the University of Illinois
Champaign-Urbana, and they have won numerous awards for their work. Testing is being done at the Rehabilitation
Institute of Chicago and other institutions. They also hope to find mainstream commercial uses for the technology such
as silent cell-phone communication. Their work has been self-financed to date, but now they are planning to seek venture
Callahan recalled one man with cerebral palsy who communicated by touching a computer screen with a pointer mounted to
his head. Callahan fitted him with an Audeo speech device and urged him to say the word "yes." On the computer screen,
the man said he never had spoken before. "In a short amount of time, we had him saying single words and then moving into
phrases, and that was the first time he had had a seminatural experience of actually speaking," said Callahan. The man,
who had been born with cerebral palsy, was in his mid-60s.
"It doesn't take a big stretch of the imagination to see why we're doing this -- if you think what your life would be
like if you couldn't say anything for the rest of it," Callahan said. "Knowing that any one of us could be in that
situation and that there are already people in that situation, that's just a huge motivation."
No date has been set for the commercial production of the wheelchair, Callahan said, but he hopes to license it to a
wheelchair manufacturer in the future.