Help Identifying Sound

Please forgive me, I know I can't give you a whole lot to go off of, but I am hoping there might be someone on this site with enough Prius experience to identify this sound based off of only a description. Here's what's happening.

Within the past couple of weeks, I have noticed a slight whine develop during acceleration. The whine immediately stops when the accelerator is released. The whine is very faint (so faint that I have no way of getting an accurate sound sample), and it sounds very much like a power steering pump or a pulley/bearing.

Further background, I replaced my serpentine belt about three or four months ago. When the noise developed, I suspected that I may have overtightened the belt and put too much stress on the water pump bearing. I checked my other Prius' belt, which was noticeably looser, and matched the tension. I know that if I did damage to the bearing, loosening the belt would not magically fix it, but I also believe it couldn't hurt the situation.

My suspicion is that the sound is related to the water pump bearing going bad. My questions are is this a reasonable assumption? And have any of you seen this in the past? Any help you can offer is much appreciated.

 

FYI, it was the water pump. The bearing was showing early signs of failure, but hadn't given out completely.

Replaced the pump, sound is gone, and all is good.