Toyota Repair: 02 Highlander AWD Rear End Road Noise

Question
Ted, we have an '02 Highlander Limited AWD with 170K miles.  Recently noticed increased cyclic road noise from the rear drivers side (I think).  Kind of like a woo-woo-woo that you can start to hear at 15-20 mph and increases with speed.  Thought was due to the tires needing replacement, but just did that but the noise remains, so I'm thinking its a hub bearing from other discussion I've seen.  

Is there any way to be sure that it isn't something else instead, like a pinion bearing?  I'm a do-it-yourselfer and would hate to throw time/money at a hub bearing if that wasn't really the problem.

Many thanks.

Ken

Answer
It's most likely a wheel bearing since it is coming from one side, a pinio bearing problem will usually be a more steady noise, not rythmic and will increase/decrease on acceleration/deceleration, while driving it put the transmission in neutral if the noise stays the same it's the wheel bearing.