2007 Toyota Corolla funny squeaking noise

Noises problem
2007 Toyota Corolla 30000 miles

My corolla is making a funny squeaking noise constantly. I don't hear it when I go over 30 mph, but that might be because my car is faster and louder. I really notice it when it is going slow or stopped. It sounds like it is in rhythm with the car. The faster I go, the faster the squeaking. The slower I go, the slower the squeaking. I hope it is not an expensive repair. Thanks.