We'll list all of the audio logs here. Note that this section is divided up by chapter and then by audio log number. Man, I love the audio logs. But why are they all in "you know whose" voice? Something here doesn't add up...
Chapter 3: Claws of the Horde
o Audio Log #1: Experiment No. 4
Where to find it: In the main village is a wagon, and to the right of the wagon (a little ways past it) is a large house. Up on the second floor is the room where the doctor is hiding out in the ceiling (you get a scene when you go up there for the first time). This audio log is right under the doctor's hiding spot.
Chapter 5: Inner Recesses
o Audio Log #2: Assimilated Consciousness
Where to find it: In the chapter you'll eventually come to a blue tile room. This is the area where you must look through tiles and solve some puzzles. In the third room you enter (if you go left to right; this room is the first one on the right), you can find this audio tape in one of the corners.
Chapter 6: Losing Grip on Ourselves
o Audio Log #3: Ernesto Victoriano
Where to find it: Once you reach the marketplace (the area with the giant angel statue and all the stalls on the right), search the right side of the stalls to see this audio log sitting in plain view.
Chapter 7: The Keeper
o Audio Log #4: Guardian
Where to find it: In the hub area of the catacombs (where you have to put all of the old lithographs in the central stone wall to continue), head down the stairs on the right (after putting in the first lithograph) and search the room you come to to find this audio log.
Chapter 8: A Planted Seed Will Grow
o Audio Log #5: Case Study: AlterEgo
Where to find it: After you pass the section where the wall was shooting spikes at us you'll squeeze through a narrow area to a room. Search the left side of the room for this audio tape.
Chapter 9: The Cruelest Intentions
o Audio Log #6: Case Study: Psychic Barriers
Where to find it: This is in the mansion, in the upstairs. Follow the hallways all the way to the back of the house, past the bathroom and down the next hallway. To the left is a room where you'll find this audio log. It is the room that connects to the main lobby of the mansion (an enemy bursts through this door to open it up for you: it is previously locked from the main lobby). Be sure to grab it before finishing the brain puzzles in the mansion.
Chapter 10: The Craftsman's Tools
o Audio Log #7: Laura
Where to find it: After getting through the door that the second battery opened (and dealing with those two ogres), you'll head through some hallways (one will launch everything up to the ceiling) and then into a room with a bed. Look for this audio log on the bed.
Chapter 11: Reunion
o Audio Log #8: Searching
Where to find it: Once you get into the office area (the large working space), check the back left corner for this audio log. There is a save door nearby and vending machines you can get green gel from (just to be sure you are in the right place).
Chapter 15: An Evil Within
o Audio Log #9: Imprisoned
Where to find it: Near the start of the chapter you'll have to go down a ladder and this tape will already be playing. It isn't often that you hear tapes, so you'll know it right away. Head through the chain link door and at the intersection you can go left to find this audio tape on a barrel. Play it again if you wish.
o Audio Log #10: Betrayal
Where to find it: After getting through the sewer section and going up a set of stairs there will be two doors. Head into the first door here to find this audio log in the back of the room just waiting for you!