I get the exact same thing man. When I run The Sims 3, I can hear a high-pitched whine that changes pitch when the cinematics change at the beginning of the game. However, I'm experiencing much worse problems than that at the moment with my computer. D:
Its called coil whine, I had the same problem with my old coolermaster real power m700, I have no idea whether its something to worry about or if its simply just annoying. Anyway I brought a Corsair HX850 which has solved the problem.