“…military engineers are currently working on a way to use microwave weapons to transmit specific, spoken words into people’s brains as a form of psychological warfare.”
—Dan Robitzski. “Those Mysterious Attacks In Cuba Probably Involved Weaponized Microwaves.” Futurism.com. September 4, 2018.
We can finally narrow it down to something between 300 MHz and 300 GHz.