Airbus Electric Motor sounds
 

Whenever I fly as a PAX on an Airbus variant on the ground, I hear some kind of an electric motor (I believe it might be to open/close the baggage compartment doors). Almost every one sounds like the motor is intermittent-- like an electric car starter on a low battery with someone trying to start a stubborn car in an early morning, or as if someone is forcing something, and then afterwards it sounds smooth. Maybe someone understands what I am talking about. What is it and why does it sound like this. I often see the faces of other PAX thinking (what kind of a piece of junk is this?)

In case you only want the short version: It's not an electric motor, its a motor-pump-combination transferring hydraulic power in between two seperate circuits.