Have any of the pullys got any play in them?
Yes you can heer the abs pump from inside the car but it shouldent be running all the time
It should only come on after 4-5brake presses and even then should only run for a second or two
If it rises with revs its engine and its Components related or if not as said abs pump try pressing the brake a few time then you hear the abs pump spring to life its just below the fuse box its is noisy but unless its making a grinding struggling noise dont worry as for engine check fan belt and pulleys inc sir con and alternator