The Frey Effect

Microwaves heard as clicks and words inside the skull — published physics since 1961. The applications section stayed thin.

Allan Frey published 'Human auditory system response to modulated electromagnetic energy' in the Journal of Applied Physiology (1962): pulsed microwaves produce clicks and buzzes perceived inside the head, without acoustic sound — replicated, mechanism (thermoelastic expansion) established. Speech transmission via the effect was demonstrated crudely (Sharp & Grove, 1970s reports). It is the physics doorway every voice-to-skull claim walks through, and the mechanism NASEM considered for Havana Syndrome. Links both files.