Extremely Odd Occurrance

[TopCliff]

Okay, I know this may sound a little weird, but just a few minutes ago, when I was saving the game, my computer made a bunch of noises that sounded like birds chirping. I turned off all the sound (music, FX) and when I saved again, it still started, well, chirping. I was just wondering if anyone else has had this problem, because it's a little annoying and creepy where in the middle of the silent night, birds start chirping. And yes, it's not coming from outside. I put my ear to the speakers and heard it coming from there. Oh, and the only program running is SC4. I appreciate any, um, knowledge of such an occurrance.