Last night I was playing a game on the Xbox 360 when I suddenly started hearing a weird voice that sounded like it was coming from the wall. I couldn't quite understand what it said but it was just a few words, like "(something) (something) back." The game did have sound effects and music going on, but this voice didn't fit at all, and it was talking at the same time as some of the conversation in the game. I was so surprised to hear the voice when I was alone in the house that I sat bolt upright on the couch and looked around.
My first thought was that maybe it was a glitch in the game. Maybe a bug had triggered a sound file to play at the wrong time. But that didn't really make sense because the voice was so unlike all the other voices in the game, and it didn't even sound like it was coming from the game at all. I wondered if I just imagined it -- it was getting to be pretty late, maybe I had started to drift off to sleep without realizing it. I kept playing.
A few minutes later I heard the strange voice again, saying "(something) exit." Again it didn't fit with the game at all, and now I was really starting to wonder what was going on. I couldn't come up with a theory that fit. Someone was hiding in my closet and mumbling? The TV was picking up another signal from somewhere else? It was a ghost? I was hallucinating?
Another few minutes passed and the voice clearly said "Newline. Exit."
Wait a minute, I thought, what kind of a ghost or intruder says "newline?" That must have something to do with the computer. I went over to the computer and discovered the answer to the mystery.
Hours earlier I had set up the computer to send its system audio to the stereo. I had forgotten to turn this back off. I had also forgotten to turn off the stereo and the computer. And one of my cats was sitting on top of the keyboard, pressing keys that were activating various menus. Somehow the random keys the cat had pressed had turned on text-to-speech audio options, and then every few minutes when the cat walked on the keyboard and typed some more, the computer would "say" various things and send it all through the stereo.
I was amazed by how the weird series of events required to create the "ghost" had all come together: the computer and stereo left on, the application that sends system audio to the stereo left running, the cat on the keyboard pressing just the right keys, other noises making it hard to tell where the voice was coming from, and me alone in the house, not looking in the direction of the computer.
Or maybe the cat was doing it on purpose, and the next time this happens the voice will say "give me more leftover salmon."