Let's admit it, Mavic Carbone SL wheels, and any other deep dish wheels are incredibly sexy. There is no ifs ands or butts about it. They just are, and they are a young mans game. But one seriously annoying thing about them, besides the crosswind factor and the weight, are that they are really fricking loud! Yes, they make that confidence building wooooosh wooooosh noise as you gorilla them up to speed, but they also make a crazy loud noise everytime you hit a bump. Going through Belmont, where the residents are too elitist to have the roads repaved, is like riding through a loud landmine where my wheels are the instrument and my shattered soul is the audience.
Why does this happen?
The outer diamter of the tube valve does not match the inner diameter of the valve hole. As you go over a bump, the shock allows the valve to smack against the side of the valve hole, making a noticeably loud, scary, and annoying noise to all those around you.
In the past, others have tried using tape to keep the valve from doing its thing. I came accross a much more elegant solution while at the hardware store. Observe...
For a mere 23 US cents you can buy these rubber O-ring donuts. Yes I do realize that an o-ring failure caused the Challenger crash, but I doubt that we will be riding in sub 200 degree weather. Find one that fits perfectly over the valve stem. Do not focus on the phalic nature of this procedure. Pull the o-ring down so that it rests between the valve and the valve hole.
It
should fit snugly between the valve and the valve hole, thus
restraining the valve stem and silencing your awesome wheelset.
If the valve stem is threaded, I will screw the metal washer that
comes with the valve stem to really secure the o-ring. 
1) How to keep your Mavic Carbone SL quiet.