A variety of things could cause your tires to make noise. It is important to notice at what times, what speeds and under what conditions, the noise is made.
The most common cause of a humming sound from ties is uneven tire wear. This is likely if the noise shows up after you have rotated your ties, or have not rotated them in a long time. Try rotating the tires again, if necessary, and according to manufacturer's directions, which should help. Buying new tires is the other alternative.
The problem could be more serious than simple tire wear. If the sound never changes, or happens more when you change lanes, the problem could be a wheel bearing. A wheel bearing problem will be constant and more a grinding sound than a rubbing sound. Eventually, a bad wheel bearing could make your tire fall off and cause an accident.
A third possibility is the balance of the tires. An out-of-balance tire can develop "cupping," which deforms the tire and can cause it to make a sound. If balancing does not clear it up, you need new tires.
