Radio on imac

Hi.
A few weeks ago my little son played with keyboard of my computer. Sundently the computer starts to play radio. Now, every time I turn on my computer it immediately starts the radio. I've tried to turn it off but unfortunately I give up. It is not necessary to open Safari, only to be connected to internet.
Some one could tell me how to turn off the radio?
Thanks.

Luis

Make sure Itunes isn't running?

Thanks for your reply.
Itunes is turned off. Rarely I turn it on.
I've turned off all programs, but it still plays radio.

Regards

Luis

Check all your wires and cables connected to the computer. Sometimes a bad one will pick up local radio. Happened to me a couple years ago, local Mexican station came in through my speakers.

Bring up activity monitor and see if there's a program running you don't remember installing - maybe he installed one for you. Do you have pandora or a radio app installed?