Once a phone is placed in the device, it automatically generates ultrasonic noise that overwhelms the phone’s microphone, making it impossible to capture a clear recording. The ultrasonic interference remains inaudible to human hearing while still allowing the phone to function normally for communication. Device provides powerful protection against eavesdropping via microphones in mobile phones, dictaphones, and other smart devices. Ultrasonic noise is the most effective defense against eavesdropping, as it overwhelms the microphones, rendering all recorded sound unusable.
