U.S. Patent 6,470,214 (2002), assigned to the Air Force: a method for producing intelligible sound inside a person's head using the radio frequency hearing effect. A patent, not proof of use.
A modulation process with a fully suppressed carrier and input preprocessor filtering to produce an encoded output; for amplitude modulation (AM) and audio speech preprocessor filtering, intelligible subjective sound is produced when the encoded signal is demodulated using the RF Hearing Effect.
U.S. Patent 6,470,214 (2002), assigned to the Air Force: a method for producing intelligible sound inside a person's head using the radio frequency hearing effect. A patent, not proof of use.