Apple iPhone 3G

I get this too with my Iphone. I think it has to do with ATT sending information back in forth with your Iphone. So like the static starts for me when I am right about to get a text message. Its not just you.

What you are experiencing is called Electro Magnetic Interference or EMI. It is actually quite common for smartphones and some other cell phones to cause EMI with radio speakers, computer speaker, and other types of sound equipment. It isn't just AT&T, other cell companies have the same issue. And yes, it is usually the way the cell phone networks communicate with the phone that causes it. When I had a RAZR and KRZR, it didn't happen much if at all. But my iPhone and Blackberries are notorious for this type of interference.

It's related to EMI (electromagnetic interference) from the GSM radios in your phone. This problem seen in nearly every GSM phone, and rarely in CDMA phones. The GSM phones require far more power to transmit/receive than CDMA, and the EMI interferes with electronic devices. Generally it is a buzzing sound that may have long beats, then rapid short beats intermittent. Super annoying, but if you move the phone away from your speaker source, the sound goes away.