Now that I have an iPhone on my desk, I’m constantly reminded that GSM radios produce a buzzing sound when they’re near speakers or other phones. I’ve had various other GSM devices on my desk lately, but have generally placed them on the other side reducing the buzz. However, the iPhone is close to my Mac, so I have to turn off my speakers and remember to turn off (or move) the iPhone whenever I speak on the phone (landline). I’m amazed that this issue is still around. My main cell phone is a Sprint CDMA phone and never hear this buzz.
Try http://www.stopthebuzzin.com. Simple product. Eliminates the buzzing.