Detecting Speech Without Microphones

kyle90 writes "New Scientist is reporting on a new way of detecting speech without using microphones, using electrodes places on the neck that measure muscle activity and nerve impulses. Apparently the user doesn't even need to speak the words out loud in order for them to be detected. This looks like pretty neat technology; if used with cell phones it could give the user a little more privacy, and the rest of us a little more peace and quiet."

Re:Huh?

[InternationalCow]

It works by virtue of the fact that your motor cortex plans ahead. So, even while you have not yet consciously taken the decision to speak yet, your motor cortex has already set up the appropriate commands and sent them out to the nerves involved. This translates to an increased firing rate in these nerves, which is not enough to move the muscles but will be sufficient to register on sufficiently sensitive equipment. In fact (other discussion entirely, but fascinating nonetheless) most of our "voluntary" decisions appear to be made before we become aware of them. So much for free will :)

How very 1980's.

[Conor Turton]

Jesus...living in the 80's? Military radios were using throat mikes back in the 80's.

Re:Vocal cords

[Zenmonkeycat]

It's not working based on the movement of the vocal chords, it's working based on the electrical impulses sent from the brain to muscles in the throat and mouth. I'm sure that the tension of the vocal chords could be measured, but the chords themselves don't have to be moving.

Vocal chords themselves are not resonators, they simply excite motion in the air. The throat, mouth, nasal passages and sinuses are the resonators, sort of like the body of a guitar resonates with the sound excited by a string being plucked.

Swiss army has had these for a while

[Anonymous Coward]

We use it usually in places with noise like tanks. The receiver doesn't hear any background noise. Would be great for night clubs :)

Re:How very 1980's.

[Monx]

Jesus...living in the 80's? Military radios were using throat mikes back in the 80's.

RTFTitle: Detecting Speech Without Microphones.

Get it? There's no microphone.

Re:Bone-induction Mics

[don.g]

Bone induction microphones do *not* read from the nervous system. They pick up vibrations in your bones (typically jaw bone, I think, but I could be wrong). Your ears do the same thing, which is why you sound different to how you normally hear yourself when you record your voice and play it back - you're missing the sound conducted by your bones to your ear.