A research team at the University of Chicago in the US has developed a wearable bracelet for eavesdropping that can protect personal information by deactivating microphones such as smart speakers and preventing eavesdropping with ultrasonic waves.
The product developed this time is a bracelet-type device equipped with 24 speakers and transmits ultrasonic waves in all directions. Although this ultrasound is inaudible to the human ear, it becomes white noise in the microphone and other sounds are not heard. Radio waves using ultrasonic waves have existed before, but due to the strong directivity of the ultrasonic waves, it could not be effective if it was not placed in the direction of the microphone accurately. Therefore, the microphone hidden for eavesdropping purposes had no meaning. In addition, the omnidirectional cover type also causes a dead angle to cancel each other. It is said that this product can move the square according to the movement of the wearer and obtain a higher effect.
There is no plan to commercialize it yet, but it is said that it can be manufactured for about $20. The research team has already revealed that inquiries are coming from a small number of investors. The prototype looks a bit deformed, but it can be useful if you have conversations where you have to worry about eavesdropping. However, if you accidentally turn on the switch from the outside, it may interfere with the calls of people around you, so care should be taken in handling. Related information can be found here .