Why do old houses make so much noise?
Thereof, why do I hear random noises in my house?
If the sound is coming from the walls, it could be a "pressure hammer" —air pressure in the water pipes. The sound doesn't have to be anywhere near that toilet or faucet, either. Since the pipes run all through the house, turning on a faucet in the kitchen could lead to a banging sound under the bedroom.
Regarding this, are house noises normal?
Certainly, some of the sounds you hear in your house are totally normal (your fridge intermittently running, the occasional creak of the house settling) but there are others that are cause for concern — indicators of what might need to be fixed, replaced, or even exterminated.
Most common reason for a house settling is improperly backfilled soil. Actually, houses do settle. When they begin a downward plunge, joints and floorboards can creak, which accounts for the mysterious sounds in settling homes ( No ghosts). And given a long enough time line, all houses eventually will settle.