Car makes a buzzing noise when in motion.

I have a 2002 Chevy Monte Carlo ss with about 59,000 miles on it. The problem is, when I am driving about 30 mph or more, my car makes a loud buzzing noise as if I were drving on mud tires, or those bumps on the side of a highway that are supposed to wake you up if you doze off the road. When i turn the wheel to the left the buzzing stops and becomes more apparent when I steer to the right. What could this be and how do I fix it?