There are 3 key sounds in FPEInteractionManager: JournalOpen, JournalClose, and JournalPageTurn. If you replace these sounds, be sure to keep the filenames the same as they are loaded at runtime from the Resources folder.
Each Pickup type Interactable object has 3 sound banks that can be optionally specified: Pickup Sounds, Put Back Sounds, and Impact Sounds. If more than one sound of a given type is specified, a random sound will be played from the sound bank.
Impact Sounds are played any time the there is a physics interaction with the object. For example if you drop the demoBall object in the demo, it plays a sound when the ball bounces. The sound's volume is adjusted based on the stength of the impact.
If no sounds are specified, generic sounds are loaded from the Resources folder. These sounds apply to all Pickup objects that have sounds enabled but no sounds specified.
There are also additional sounds played by Audio Diary asset type, the FPEGameMenu, and related UI elements.