Following your phone’s safety hearing limit while using microphones, might not be enough to stop the slow damage on your ears. It seems, train stations, shopping centres, museums and libraries could be making people ill by exposing the public — without their knowledge — to airborne ultrasound and very high frequency noise (VHF), a new study has revealed.
The study, published this week in the Proceedings of the Royal Society, suggests that mass public exposure to ultrasound and VHF could be causing “ultrasonic sickness.” The symptoms of which include, nausea, dizziness, stomach pain, tiredness and headaches. The problem with ultrasound is that it is in the frequency of 20 kilohertz, mostly out of people’s hearing range. Researchers recorded frequencies at locations where members of the public have complained of headaches, migraines, nausea, fatigue, dizziness and an uncomfortable feeling of pressure in the ears.
Peculiarly these sounds were picked up at a public library with an annual footfall in excess of 1.6 million people, and in a museum with over 3 million visitors per year.
Professor Tim Leighton of Southampton University’s Institute of Sound and Vibration Research, who authored the report, warned of the “massive increase” in deployment devices or loudspeakers in residential, recreational and occupational places, which expose members of the public to ultrasonic sound without their knowledge and without official regulation.
“The current lack of evidence makes it unlikely that clinicians will consider VHF and ultrasound exposure to be a possible cause when confronted with patients experiencing these symptoms,” wrote Leighton in the report.
“The current guidelines in place are based on an inadequate research base, and occupational guidelines are being applied to public exposure,” Leighton continued.
Leighton stresses the urgent need to impose more stringent and to ensure that the new guidelines provide ample protections, stating that the research behind the existing set is “not sufficiently substantial”.
While, concern and research regarding airborne ultrasound harm began in the 1940s, however this research was focused largely on the effects of ultrasound from jet engines, dental drills and cleaning baths.
Professor Bruce Drinkwater of Bristol University’s Department of Mechanical Engineering however disagrees. “Whilst I agree with Prof Leighton that the the evidence base surrounding ultrasonic sickness is poor, I’m not convinced there is much of a problem,” Drinkwater told Mashable.
“A few anecdotal cases do not prove anything as we are exposed to many potentially harmful things each day, including traffic fumes, flashing lights, and vibrations,” he continued.
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Author: Technology Blog
