Public being increasingly exposed to airborne ultrasound, research says

Scientists at the University of Southampton found increasing exposure in railway stations, museums, libraries, schools and sports stadiums, in which complaints of nausea, dizziness, migraine, fatigue and tinnitus have previously been reported.

Ultrasound, sound waves with frequencies higher than the upper audible limit of human hearing, can be generated in public places from a number of sources including loudspeakers, door sensors and public address systems.
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