I recently noticed that my new Macbook Pro 15" Retina is making a strange creaking noise. I'm not sure if it is the fan or not, but it sounds like the fan is running really low or trying to start up. Here's a link to the sound I'm hearing: https://soundcloud.com/tyler-james-hienkel/macbook-pro-creaking-fan-noise It's pretty faint, but annoying when I'm in a quiet room. I noticed it tends to happen right after I move the laptop, but I'm not sure if this is a causation or just a coincidence. Is this sound normal?