Mine has sound, but only when playing a game, and because it's placed on my console shelf made of wood. Other than that, it should be fine. I've also found that it makes less noise if you don't use the stand, and just let it lie horizontally.
I've taken the Wii to other places too, and it's "silent as a Ninja" (as one person put it :P) there. If it gets too bad for you either place the Wii in a different spot or try taking it around a friends house to see if it's just where it's situated.