In 1969, American composer Alvin Lucier recorded "I am sitting in a room" — a haunting, 15-minute piece that takes audio reproduction to new, mesmerizing extremes. Lucier began by recording himself reciting a text, in which he explains the premise of his experiment. He then played back that recording, recorded it, and repeated this process several times. Because Lucier conducted this procedure in the same room, the room's resonant frequencies reinforced themselves with each re-recording, muffling the artist's voice, and eventually rendering it unrecognizable. It's basically a slow, chilling aural decay, and it's well worth listening to.