The problem here is you can't do a good job of this without lifting the carpets. How can you figure out where the joists are without doing this? (I'm presuming this is an upper floor of standard wooden joist construction.)
There are a number of options open to you to resolve this, and previous threads here have touched upon them, including screwing the offending boards down securely or dusting the joints with talc or the like to reduce the friction, but all proper solutions require the carpets to be lifted.
Is there a reason you don't want to lift the carpets? In most cases they can be replaced easily enough.
Leo