sometimes my computer will make the occasional "whrrrr" or "vrrrrrrrrmmm", but in the past 10 minutes, it's made two sounds which I can't even comprehend. it's like the sound of a train whistle or a harmonica. it wasn't the normal whirring of fans or anything, it actually sounded like a harmonica. no tv is on in the house besides one on the other side of the house which is quiet as stuff, and nothing outside made it unless there's a car with a train horn. it did it twice in the past 10 minutes and it did it at random times, but I think it's stopped now. what the forget is it