you might hear a rumbling from the wheel as it rolls... the spokes resonate with the roughness of the bearings, and sing in harmony to that rumble's frequency.
other noises usually mask the tones though...

best to remove the wheel from the bike and rotate the axles to check quickly.. and add side force if the axle is a bit loose.. the looseness will hide the rough cone feel.

remove, clean and re-grease, inspecting the cones once they are cleaned... ANY pitting or galling means they need replaced, along with the bearing balls.
Grade 25 bearings are far better than G-100