Microwave auditory effect (Frey)

The microwave auditory effect (MAE) refers to the mental perception of sound that is caused by exposure to pulsed or modulated radio frequencies (i.e. pulsed microwave radiation). It is also known as the Frey effect for Allan H. Frey, the American neuroscientist who was the first to publicly publish a paper on the phenomenon.

Reading

• Frey, Allan H. (1 Jul. 1962), "Human Auditory System Response to Modulated Electromagnetic Energy", Journal of Applied Physiology 17 (4): 689-692, https://doi.org/10.1152/jappl.1962.17.4.689  — "The intent of this paper is to bring a new phenomenon to the attention of physiologists. Using extremely low average power densities of electromagnetic energy, the perception of sounds was induced in normal and deaf humans. The effect was induced several hundred feet from the antenna the instant the transmitter was turned on, and is a function of carrier frequency and modulation. Attempts were made to match the sounds induced by electromagnetic energy and acoustic energy. The closest match occurred when the acoustic amplifier was driven by the rf transmitter's modulator. Peak power density is a critical factor and, with acoustic noise of approximately 80 db, a peak power density of approximately 275 mw/ cm2 is needed to induce the perception at carrier frequencies of 425 mc and 1,310 mc. The average power density can be at least as low as 400 μw/cm2. The evidence for the various possible sites of the electromagnetic energy sensor are discussed and locations peripheral to the cochlea are ruled out."