Alien: Isolation MADDOGG Gameplay Series Pt.3.

Instead of following a predetermined path, the artificial intelligence of the Alien has been programmed to actively hunt the player by sight, sound and smell. The Alien AI was programmed with a complex set of behavioural designs that progressively unlock as it encounters the player to create the illusion that the Alien is learning from its encounters with the player and adjusting its hunting strategy appropriately.
This includes the ability for the Alien to investigate "secondary sources" of disturbances; for instance, if it notices a locker or air lock is open, the Alien will search for who opened it. The Alien emits vocalisations the player can hear to gain understanding of its current intentions; a scream may indicate that the creature is about to attack, while other sounds may indicate the Alien has seen something, is searching or has lost all trace of its prey.