The Macbook doesn't mind making noise. The optical drive 'is there a disk in me?' check is the most annoying noise, the startup 'boing' a close second -- and neither easy to 'mute', as far as I'm aware. (The latter won't happen if the sound is off on the laptop when it gets shut down, but that doesn't really count in my mind.)
It was so nice to turn the computer on this morning and hear... nothing.