The system uses brain electrodes to read signals meant for jaw and mouth muscles. An FM radio is used to transmit these brain signals to a computer, which transforms them into recognizable sounds. Currently the system is only able to produce vowels, but with more electrodes and more powerful algorithms it should be able to scale up to fully vocalized words.
Of course, nobody is getting a free lunch here. "Although the proposed engine will consume energy for manipulation of the particles, the propulsion will occur without any loss of mass," says Feigel. He even suggests, with masterful understatement, that this might have practical implications.
So basically, you can create thrust by interacting with virtual particles that don't actually exist. It's not quite a zero-point generator, but it still relies on pushing against fiction.
I guess it works basically the same way as turning electricity into thrust by pushing against a planetary magnetosphere, but without the planet?