Should you be able to hear a power adapter?
I'm guessing the answer is no. But if I hold the my Apple Magsafe adapter up to my ear, I definitely hear it. There's a drone with a high pitch hiss and low pitch rumble, punctuated about once per second by a lower buzz. I think there's a loose connection, because sometimes I have to jiggle the wire where it connects to the adapter. I really hope this doesn't spontaneously combust while I'm asleep.