Question: I live in a 3 bedroom shared house and want to reduce the noise that the bathroom door makes when it closes.

I tried to find a photo of the door. It's basically a old mansion block of apartments in London. The door has a brass knob and stained glass is about an inch thick wooden. I don't know if you can picture the old type of door I am describing? It's very badly sealed. When the door is closed it makes a loud sound when the door touches the door frame, then you twist the knob and then it springs back slightly - all the doors inside the apartment are the same and this one wakes me up at night.

Any ideas?

Answer: 
I guess you could try putting some thin foam or felt stick on pads on the inside of the door frame where the door contacts it. This should lower the sound of the wood to wood contact. If the knob hardware is also loud, try using some dry silicon spray lubricant on the moving parts and on the door hinges. Sleep well.....
Get narrow weather seal and put it on the door jamb so the door never touches the wood.