Vibration and humming noise in 2005 Nissan.

Have the wheel bearings checked. Some alignment shops offer a FREE front suspension check. If you can locate one, have that done; but don't buy any parts or services until you post the results here for further assistnace.

If you can't find someone to do it for free, try this.
Raise the front tires and grip the tire at the 3 and 9 o'clock position and try to shake the tire inward and outward. If there is movement, suspect a loose wheel bearing (but get a better view while a friend shakes the tire). Repeat on both front and rear wheels.
(on rear wheels push the tire in toward the other side of the vehicle and pull out as well--checking for play in the axle bearings and differential)