telephone and radio interference

When calling my local radio station to win free stuff (and make program requests), why does my phone cause such an interference with the radio frequency/reception if I don’t turn my radio down? Thanks!!!

Probably because of feedback. The sound from the radio goes into your phone, and if your call is on the air then the radio sounds that went into your phone are rebroadcast on the air, then go back into your phone, and you get a feedback loop which sounds like real mess.

It’s feedback distortion. The audible sounds coming out of your radio are picked up by your telephone’s microphone and sent back to the radio station on the call you’re making. When they put your call on the air, their own broadcast comes back to them and is played out over the air again. This comes out of your radio and is picked up by your telephone’s microphone, and so on.

This is referred to as a positive feedback loop. The same signals are being re-amplified in a non-ending loop until the system is overwhelmed and amplifiers are driven into distortion.