A closer look
Paranoia is a lucrative industry, especially when you can sell people a gadget that screams at frequencies only dogs can hear. Ultrasonic scramblers, sometimes branded with needlessly aggressive names like 'Phantom Terror,' protect private conversations from hidden microphones by emitting a barrage of high-frequency acoustic noise. While humans can't hear a thing, the ultrasonic waves overwhelm the diaphragms of digital microphones in smartphones or smart speakers, turning whatever secret you're whispering into an unusable wall of electronic static.
