I have the Macbook Pro that keeps making a constant white noise right after the machine boots up. The sound is loud enough when I am by myself that it totally distracts me. I have had 3 mac laptops before and this is the loudest one by bar. After I compared my machine with a close friend who has an exact machine (same late October last year generation), I realized that the machine had some issues.

I took it to the apple store. They said they tested it and could not "hear" the noise. So they wouldn't do anything about it. Yet when I put my macbook pro next to any laptop, everyone can tell my laptop is the loudest.

I have become one of their disappointed customers.