Toyota Repair: 2003 Toyota 4Runner Whinning Noise, power steering pumps, 2003 toyota 4runner

Question
QUESTION: I own a 2003 Toyota 4Runner and I have noticed a certain whinning noise coming from under the hood. It is distinguishable when the car is idling but really noticeable when you accelerate going down the road. The vehicle has 155,000 miles, in the last year I have replaced alternator and battery done at Toyota dealer. Thank you for taking the time to look at my question

ANSWER: Has the timing belt and water pump ever been replaced?

---------- FOLLOW-UP ----------

QUESTION: No it has not. Everything on the car is original except the alternator and battery, I have never had any other problems. I had the hood open and had my wife step on the accelerater almost sounded as if the noise could be coming from the area around the alternator. Could a bearing be going bad?

Answer
Try to eliminate the noise by removing the drive belts one at a time, if the noise disappers when removing the alternator belt then that's the problem, do the same for the a/c and power steering belt, make sure the power steering fluid is not low, I have seen a lot of power steering pumps cause this noise, very seldom the alternator.