2005 Chevrolet Malibu humming noise

This is extremely common on any car brand. A front wheel bearing is noisy. Half shafts don't make noise except for a little clicking when the outer joint is severely worn.

One word of warning. The replacement bearing will instantly become noisy if proper installation procedures aren't followed. In particular, there must never be any vehicle weight on the bearing unless it is torqued to specs with a click-type torque wrench. Most bearings call for around 180 foot pounds, but some GM models are as high as 240 foot pounds.