Toyota Repair: Drive belt train bearing noise 2000 Corolla, engine whine, corolla ve

Question
2000 Corolla VE, Automatic
Engine whine when driving; whine still there in neutral with raised rpm.
Car was in shop for something else and I asked what they thought might be causing the noise.
They diagnosed two noises:
(1) A low frequency pulsing due to a defective belt tensioner damper (New tensioner assembly $460 installed).  I now think I can hear such a noise.
(2) A higher pitched whine due to the A/C compressor (New compressor $980 installed).
Since I can't hear any change in the whine on turning the A/C on and off, in neutral at elevated rpm, I don't believe the A/C compressor is the cause of the whine.
My question is how would you recommend determining which bearing is the cause of the whine - the water pump, the alternator, the power steering fluid pump, idler pullies, the belt tensioner or even the A/C compressor?
Perhaps first, what else might be the cause of this whine - it is not a high pitched whine, rather a low to medium frequency whine, certainly not a squealing noise.
I feel competent to change the tensioner myself, but anything else would probably be too much for me in this cold weather (Bedford, MA)

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Regards,

Peter

Answer
The low frequency pulsing noise is probably caused by a weak tensioner, toyota has issued a service bulletin for this so it's fairly common. A power steering pump noise usually changes pitch when the steering wheel is turned, it should also change when the A/C is turned on, water pump? Maybe. You can try to isolate the noise by using a piece of plastic tubing held to one ear and the other end touching each rotating component.