There are two kinds of recording blockers (recording jammers), one is ultrasonic interference (silent mode), and the other is white noise (sound noise mode) to prevent recording.
Ultrasonic interference mode: Ultrasonic wave is a sound frequency that is emitted at a frequency that is not perceived by the human ear. It does not have any harm and impact on the human body, but it will cause huge interference to all devices that rely on the sound pickup.
The frequency band emitted by it impacts the sound film of the sound head of the recording and video equipment, causing irregular frequency fluctuations on the sound film, so that the sound recorded by these devices is completely irregular noise. This is the basic principle of it. It has the advantage of being quiet and safe for humans.
White noise mode: The white noise mode is the irregular noise emitted by the device to mask the normal sound of conversation. Conversations in white noise mode should be conducted as low as possible, at a volume that is just audible to both parties in the conversation.
White noise mode is a sound interference mode, so it is only suitable for use in an open, mutually informed situation.
The recording mask emits ultrasonic waves with random noise that cannot be sensed by the human ear. When a digital device such as a mobile phone records, these noises are recorded into the digital device together with the sound of a normal conversation, making the recorded audio invalid.
The recording blocker also has the same interference effect for the audio information in the video shot, because the noise of the ultrasonic noise is generated randomly and cannot be restored, so the audio after interference can not be restored, so as to ensure that the original information is not leaked and spread. The sound produced while working is about as loud as a computer fan.
