iPhone making noise when charging

I'm getting the same thing but only through the wall adapter.

same here, chirp while sound is on, vibrate while it's off, only while plgged in to the wall. How is this a feature and not a bug?

Is the sound at all similar to the sound your iPhone makes when you first plug it in to charge?

If so, it could be that either the wall charger unit or cable is defective, or that there isn't a good connection with the iPhone's dock connector.

If the charger keeps losing and re-establishing connection with the iPhone, the iPhone will make that sound (or vibrate if it's in silent mode) as if it's being unplugged and re-plugged over and over.

Since defective wall charger units have been reported a number of times on here, that's where I would start looking.

This is a known radio-interference problem with all GSM phones (although some seem to hide it better than others).

DONT keep your iPhone right next to your computer - make sure you use the distance of the cord to keep it 2 - 3 feet away from your computer or any stereo equipment.

Same with the dock when plugged into the wall -- make sure that it is not right next to your computer or any other stereo equipment, televisions, radios, etc.

4n6doc is completely spot on (as the Brits say). I have experienced this same scenario and read elsewhere on these discussion boards confirmation of this faulty wall charger.

I took it into Apple and had a Genius test it. They saw the problem occur intermittently and without further question, replaced it with a new unit and the problems have gone away.

I will say this though, the full charge glow and the plug symbol in the charging indicator still only comes up for me when I plug it into my MacBook Pro. I think that it is still a glitch, because I have done full cycle and "top-off" charging on the cradle with the wall charger leaving a slight sliver on the battery, and as soon as I change it over and plug it into the USB port, voila! full glow and plug.

Go get your new wall charger exchanged.

That is weird. Have you tried resetting your phone? Hold down the sleep and home buttons for 10 seconds until you see the white Apple logo on the screen.