Students at MIT have developed a device, called AlterEgo, that can learn and then recognize–that is, “hear”–words that you say to yourself. Then act upon your silent instructions.

The lead developer

stresses that the device doesn’t read thoughts or the random, stray words that just happen to pass through your mind. “You’re completely silent, but talking to yourself,” he says. “It’s neither thinking nor speaking. It’s a sweet spot in between, which is voluntary but also private. We capture that.”

The device looks like a headset, but it’s looped over the ear, not in it, and no microphone protrudes, instead sensors cover some of the real estate below the mouth,

where a handful of electrodes pick up the miniscule electrical signals generated by the subtle internal muscle motions that occur when you silently talk to yourself. The device connects via Bluetooth to a computer, which then communicates with a server that interprets the signals to determine what words the wearer is articulating.

In trials with fifteen people, the device has been getting the unspoken words right about ninety-two percent of the time.

The applications would vary widely, from improving the quality of life of a paralyzed person, to changing the channel without a word or button pressed, to gaining obvious military advantages over foes who don’t have the tech.