You usually hear wheel bearings when coasting in neutral,does the noise reappear when revving the engine? If so suspect alternator/tensioner problems, if the noise only appears when in motion then it may be worth jacking up each corner in turn and have a listen to the bearings when giving the wheels a spin, don`t discount the rear either,sometimes it can be deceptive as to the exact location of the noise itself.
cdc
April 2016