Why is there a brief rustling sound on the walkie-talkie after the other one finishes speaking?

This starts with the noise of the walkie-talkie. When the walkie-talkie is transceiving, it will not only receive useful sound modulation signals, but also receive white noise in the air, as well as noise generated by the internal electronics of the device, etc. The indicator that the device can distinguish the signal is called sensitivity. When the walkie-talkie does not receive a signal, or the received signal is too weak, what enters the audio amplifier is noise, and it sounds rustling, which is the noise of the walkie-talkie.

Of course, the reason why noise occurs in wireless walkie-talkie communication is objectively related to the strength of the received signal, the distance of the communication , and even the quality of the walkie-talkie itself. Therefore, this requires the walkie-talkie to install a noise suppression circuit.

The principle of the squelch function of the walkie-talkie is that through SQL（the SQueLch circuit), when the walkie-talkie is waiting and the call is intermittent, the low-frequency amplifier is automatically locked, so that the noise is no longer output from the speaker or earphone; when the signal is input, the locked state is quickly released. , so that the signal is output by the low frequency amplifier. This can not only ensure the clear and loud voice when the wireless walkie-talkie receives the signal, but also effectively solve the problem of "rustling" sound. In addition, this can also reduce power consumption, thereby extending the use of the wireless walkie-talkie.