Do you mean, if you tap the camera with your finger, absolutely no sound comes out?
They all do. The 4 4S in my house do. The 17 on display at both my local Apple stores do.
The genius who helped me does.
My 3 old 4S that I returned did.
Thats around 50+ that all do. Now some were quiet and some were loud.
Even the iPhones 4, 3GS, 3G do too.
Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)
My old 3GS rattles. My new 4s and my wife's new 4 rattles too. It's normal!