A common complaint with high rims and especially carbon rims (because carbon has a high resonance) is that when you rotate your wheels you hear tapping of the valve against the rim. This is of course because the hole in the rim is bigger than the valve itself. A sound that can be very disturbing and even so bad that it takes you out of your concentration.
It is remedied by some by spraying a bit of sealant into the hole.
Another, perhaps slightly neater way is to press a piece of electrical tape over your valve and push it all the way across the valve to the rim, sealing the hole in the rim and leaving no room for the valve to move