It is not the fan, it is an electronic noise and the drive light flashes almost constantly. It sounds like an old fashioned computer noise, like something you'd hear in a 1970 movie sound effect. Sometimes it also makes a faint chirping noise. The fan sound is totally normal, so it isn't related to that.
I don't notice this sound when I am in the office plugged into my docking station. But I sure notice it at home! Drives me crazy!
