Even when you're asleep, your brain is constantly processing ambient audio. (observer.com)
Im not going to focus on the other MAJOR problems the game has like framerate issues whernever you turn the camera, NPCs who walk straight through each other (in cutscenes) ridiculous loading times, lack of ambient audio when moving around, constant repetitive fetch quests etc etc etc.. (metacritic.com)
All the while, Echo will be recording ambient audio in the background — even when you turn your screen off. (android.gadgethacks.com)