CB radio can be heard on AUX headphones?

I have two CB radios. One with a purchased antenna and one with a do-it-yourself antenna. While I was using the radios, I was on the phone with a friend, so I plugged headphones into my laptop. When I then sent I heard a cracking noise on the headphones even though they were not connected to the radio. Is that normal? The antennas are set up right next to my desk.

That can happen. The same effect occurs, for example, when a smartphone registers itself at a transmission mast and a stino radio is in the immediate vicinity. Then you can hear what is happening.