There are 5 channeling stones hidden throughout the map. You must progress through the game normally up to the good ending to find all of them.

Here are the locations:

1. In the intendants room, besides the TV.
   
2. In room 104, besides the washing machine
   
3. When you exit the otherworld lobby, jump the fence and go around to get under the staircase.
   
4. When you enter the chase corridor, turn around and look down to your left.
   
5. The last stone is in the refurnished apartment, hidden behind some boxes near the bedroom.