ABSTRACT

It is believed when people are exposed to very low-level RF energy with certain frequency and modulation characteristics, they report hearing sounds [1-3]. This has been called auditory phenomena or RF hearing. These sounds, e.g., buzzes, clicks, tones, etc., vary as a function of the modulation. Pulsed microwaves have been heard as sound by radar operators (who used to stand close to an antenna) since radar was invented during World War II. This was reported in one of the earliest reports about the auditory perception of pulsed microwaves in 1956 as an advertisement of the Airborne Instruments Laboratory. The advertisement described observations made in 1947 on the hearing of sounds that occurred at the repetition rate of radar while the listener stood close to a hom antenna [4]. The incident average power density at the head needed to induce the effect is quite low, in J.lW/cm2.