Yes, you are exactly right on the spot.
Today, I took it to a mechanic I trust and it turned out to be a loose wheel bearing plus a couple of other things that created the sound. First, the wheel bearing is loose on both ends of the front tires. Second, I have a not so bad bent right wheel. Third, the mechanic thought that my Bridgestone SO3 is too harsh for everday driving. All these factors contribute to the noise and vibration. So he tightened the bearings and rebalanced the tires, which dramatically increases the car's drivability. Though the noise and subtle vibration is still there, he recommended me to switch to other tire brand as soon as my Bridgestone tires are worn to further reduce the noise and vibration. Anyway, thank you for your adivce.