The bracelet. Source: Yuxin Chen et al.Amid growing privacy concerns surrounding the use of digital assistants and other smart home devices with built-in microphones, researchers from the University of Chicago have developed a wearable bracelet for preventing others from listening to conversations captured by the devices.

Outfitted with a lithium battery, a microncontroller, signal generator, power regulator, 3 W amplifier and 24 different transducers that emit ultrasonic waves, the bracelet “jams” microphones in smart devices — including in digital home assistants, smart watches and smart phones.

The wearable bracelet, according to its developers, emits ultrasonic white noise at random intervals within a frequency range of 24 kHz to 26 kHz, interfering with microphones, even concealed microphones, in virtually every direction within a space.

Currently, the bracelet is just a prototype and still needs to be reconfigured to make it appropriate for everyday use. However, its developers believe that the bracelets could be manufactured for as little as $20 each.

The University of Chicago team detailed the technology in a paper for ACM CHI 2020, titled "Wearable Microphone Jamming."

To see how the device works, watch the accompanying video that appears courtesy of the University of Chicago.