The game designers admitted that these were designed as supplemental material rather than essential, as they could not be sure that the player would listen to them. But they contain great background material about Rapture. The discovery of Adam from a sea slug. Steinmans decent into insanity. Brigid Tenenbaums growing guilt over her actions. How the civil war builds. Maybe you dont need to hear them to play the game. However, that they exist at all is a testament to the fact the makers wanted to produce something greater than a standard game.