E4300 Random Noise

I have Latitude 4300 that will make a nigh pitch crackling sound from time to time.  It happens every 5 min or so.  It only happens when there is activity on the Laptop.  I have replace the memory, motherboard, processor.  I have removed the bluetooth.  It happens when the laptop video is used or when it is connected to an external monitor. I have seen some post regarding the processor and hypernate mode. Any help would be great.  I have attached a file with the noise.