Bracelet of Silence

Image: Petra Ford for The New York Times

Worried about your privacy in the surveillance state? The “bracelet of silence” prevents Alexa, Echo or any other microphones in the vicinity from listening in on the wearer’s conversations. It  has 24 speakers that emit ultrasonic signals when the wearer turns it on. The sound is imperceptible to most ears but nearby microphones will detect the high-frequency sound instead of other noises.



More: The New York Times