for National Geographic News
It's technology that lets you speak your mind—literally.
NASA scientists are developing a speech recognition system that can understand and relay words that haven't been said out loud.
The system uses electrodes attached to the throat to detect biological signals that occur as a person reads or talks to him- or herself.
The signals can then be converted into text or synthesized speech.
"Subvocal speech recognition is basically the understanding of words without the requirement for sound," said Chuck Jorgensen, a scientist at the NASA Ames Research Center in Moffett Field, California, whose team is developing the system.
"We're looking at the neuromuscular patterns being sent through the nervous system and inferring from those patterns what words would have been said out loud had a person actually permitted himself to produce the acoustics."
The technology could one day be used for communication in high-noise environments or in "silent" cell phone calls.
Like "Watching" Music
Even when a person reads or mouths words silently, electrical signals are sent from the brain to the tongue and vocal chords.
Technology is under development to read similar signals directly from the brain, allowing a person wearing a special cap to, for example, operate a computer with their thoughts.
(Related news: "Man Moves Objects With His Mind Using New Sensor" [July 12, 2006].)
But the NASA team's device, Jorgensen said, focuses instead on the muscles receiving the brain's signals.
SOURCES AND RELATED WEB SITES