Shield against induction of sounds from remote source of RF

AI Thread Summary
The discussion highlights a study demonstrating that electromagnetic waves can induce sound perception in both normal and deaf individuals from a distance. The phenomenon is dependent on factors like carrier frequency and modulation, with specific power density thresholds required for sound induction. Participants noted that peak power density is crucial, with a minimum of 275 mw/cm2 needed in certain conditions. For practical shielding against this effect, materials like metal plates and Faraday Cages can provide attenuation, although they do not alter the wave characteristics. Overall, understanding these interactions is vital for developing effective shielding methods.
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It has been demonstrated that it is possible to make humans hear sounds using waves.

Abstract From Journal of Applied Physiology
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.

Is there a practical method for shielding? I mean using materials for simple attenuation, and/or altering characteristics of waves (frequency, phase and/or amplitude).
 
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A metal plate provides some shielding. For complete isolation, a closed metal box called a Faraday Cage.. But shielding does not change frequency. Phase is irrelevant.

Note that I did not mention a tin foil hat above. :smile:
 
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