Chevrolet Repair: pinging, radio interference, radio speakers

Question
I have a 2001 Malibu. I get a "pinging" through the radio speakers. It seems to have a pattern to it. Sort of like it is ringing out a code. It even sets the "voltage sensing type" alarm off. Do you have any idea what it is?

Answer
this radio interference is possibly caused by the computer signal.  Any lights on the dash come on?  Any change in performance?  Any updates to the stereo system?  Any tune ups lately?  

May be worth it to have the car scanned.  See if there is a code.  Autozone will do this for free.