What noises can you hear as a passenger?
There are loads of noises you might hear; there are fuel pumps, hydraulic pumps, air circulation, adjustment screws, servos, and on Airbus aircraft a strange clanking noise when you go over bumps in the tarmac.

On the ground you may hear (and feel) cargo pallets rolling on the hold, and the hold doors being opened and shut. In-flight you have engine noises and air flow noises.