Researchers create a ‘wearable jammer’ that blocks all the microphones around the wearer

For those who are always in fear that their 'smart' devices are always snooping on them without their knowledge, a new wearable device made by the researchers of the University of Chicago might be the most apt solution. The experimental bracelet made by the researchers makes use of ultrasonic broadcast from 24 transducers and acts as a jammer for most of the microphones (hidden or not) around the wearer, regardless of their direction.

"Moreover, our device exploits a synergy between ultrasonic jamming and the naturally occurring movements that users induce on their wearable devices (e.g., bracelets) as they gesture or walk," say researchers on the website. Also, since the wearable bracelet is in the ring-layout design, it allows the user to jam microphones of smartwatches, phones, laptops and even smart speakers easily in multiple directions.

Researchers initially faced two major drawbacks with such a device. First was that it was heavily directional, requiring wearers to point the jammer towards the exact location of the tracker. Second was that it relied on multiple transducers that although enlarge the jamming coverage, also cancelled out each other, creating blind spots. If a microphone is present in that blind spot, it won't be jammed. Hence, the researchers came with a ring-like design that can kill those blind spots with hand movements.

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Explaining how the wearable works, the researchers said that while these ultrasonic waves are not in the audible range for human beings, they leak into the audible range after being captured by the microphones, producing a jamming signal inside the microphone's circuit and disrupts voice recordings. "The leakage is caused by an inherent, non-linear property of microphone's hardware," they added.

However, the two major plus points of the wearable jammer over a static jammer is that it has more coverage and it even blocks microphones that are covered by cloths, paper, sheets etc.

Unfortunately, this is an experimental design and you won't be seeing this hitting the shelves anytime soon.