It's real. Also there is precedent from the 1960s. Patrick Flanagan invented the Neurophone, which allowed hearing through two electrodes placed on the skin which conducted modulated RF. The microwave upgrade probably uses the same pathway into the brain.

The series of diplomat incidents involving strange mental attacks probably use the same approach.

If you stand in the wrong place on an airfield near a military jet that turns its radar on while on the ground, you may 'hear' a buzzing. The same radar by the way will kill birds that fly into the megawatt pulsed beam.