That noise radios make when you push the talk button


You hear it in movies a lot, walkie-talkies seem to be the only kind that make it

In: 2

It’s called squelch. It’s basically a feedback letting you know that you’re not currently transmitting, but the radio is receiving. You’re effectively hearing the static from it “listening” for a signal

To squelch something is to mute or silence a sound. On a 2-way radio, without squelch you would hear loud static. The squelch circuit mutes that static when there is no signal. Most radios will have a setting for that, and the higher the squelch, the stronger the signal has to be to “break through”.

The little “kkkkk” sound when the signal stops is because the squelch circuit takes just a few milliseconds to kick in and stop the static. But, it also serves as a signal to the listener that the transmitter has stopped, and that you can now talk. So, even if you could eliminate that tiny sound, you wouldn’t do it because it serves a function.