pitched hum. What is it? I drive a Chevrolet Cobalt 2005 Sedan. It has been making this awful humming/vibrating noise from my tires. I sense that my wheel is bent on my driver side but my passenger side (both front) wheel makes a different higher pitched humming noise. It vibrates the car even when I am just driving. My car shakes a little when I brake, but not so much anymore. I can drive up to 40 mph but after that especially around 55 mph it gets horrifically loud and vibrates harder. I am not braking at this point, just driving. I have gotten it checked out and have gotten a variety of hypotheses. Some have said it was my transmission, some said bearings, CV joint. It gets really annoying. I don't have a fortune to spend on fixing it. 63 k miles. Fairly new Tires.