Page 24 - Fall2020

EXPOSURE TO ULTRASOUND IN AIR
or the (possibly mistaken) belief in its presence (e.g., fear that ultrasound may be causing injury, even if inaudible). Such anxiety might be enhanced if the suf- ferer knows that the exposure is involuntary, that others cannot hear it, that it will continue without their control at their place of work or home or in their child’s class- room, and especially if they think that it is maliciously targeted at them. Indeed, we have received a surpris- ingly large number of inquiries claiming ultrasonic attacks by neighbors, and we always recommend testing for such signals with a smartphone.
This article has not covered the issue of human adverse effects to infrasound or audio frequency sonic deterrents (apart from a brief mention of teen deterrents; Leigh- ton 2016a), such as LRAD devices (which currently do not emit their main signal above ~3 kHz but are some- times inaccurately confused with parametric devices and thought of as high-power “spotlights” for crowd control; Leighton, 2016a). This article also does not cover elec- tromagnetic emissions or ultrasound as applied into the body for fetal scanning. This distinction is mentioned here because these issues are frequently raised by some readers/ listeners when we discuss the adverse effects of ultrasound in air on humans, and they are outside the scope.
Acknowledgments
Financial support from the Colt Foundation (Ref. No. CF/03/15) and the European Metrology Programme of Innovation and Research (EMPIR; Grant 15HLT03 EARII) is gratefully acknowledged. The EMPIR programme is cofi- nanced by the participating states and from the European Union Horizon 2020 research and innovation program.
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