You can also hear a disembodied voice near the bathroom. It comes from just outside of the bathroom, and is best heard in Spectator mode.
Just outside of the bathroom on Asylum, exactly where the disembodied voice is heard, you can also hear a crying girl. She will switch back and forth from crying to laughing, and just like the voice, is quite disturbing.
All around the stairs that are a bit away from where the piano can be heard, you can here knocking on the wood that is covering up all the windows. If you fly around constantly as a spectator, you will hear this wooden knocking sound everywhere. It distinctly sounds like someone deliberately knocking on wood. It can also be heard on the boarded up windows on the other side of the map.