Without those headphones, he could detect every sound there is; from the flap of an insect's wings to someone's quivering heart and detect the real emotion from someone's voice, their way of speaking and their behavior. He could perceive their real feelings, the beast inside them. Its a frightening place with all those beasts staring directly at him from the abyss. So, he cranks his volume and immerses himself in music to take in the real world as less as possible.