Weird 3GS noises

[Preacherjonson]

I use my 3GS as an alarm, it's the only thing that can wake me up, I put it on a docking station so that it is louder. Now most of the time it's fine but sometimes it will be fine for a few minutes and then make a strange sound (forgive this idiotic method) kind of like du, du du du, du du du and will repeat until I take it off the stand, it does say the device may not be compatable whenever it goes on the docking station but I just dismiss the pop up. Any ideas?

 

[Dangerous Theory]

Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A5313e Safari/7534.48.3)

Try airplane mode.

 

[Gavernty]

hahahhahahahhahaha, du du du du du... so funny. Any way, is it the noise you hear in classrooms sometimes on the computer right before a cell phone rings? Like that electronic interference noise?