Help diagnosing loud road noise?

2011 Prius III
79,XXX miles

I'm trying to figure out the source of some loud road noise on my Prius. I think it's coming from the drivers side front wheel, but it's hard to tell. The noise starts up at about 25 mph and increases in intensity as you get faster. It almost sounds like loud tire noise. I can't feel anything in the steering wheel, so doesn't feel like a balance issue either.

The tires are Michelin Defenders that I bought brand new from Sears in April and have put about 4k miles on. The car was aligned at the dealership about a week later and showed no major adjustments.

I have a friend with a Prius V who offered to let me take his front wheels off and put them on my car, so I could take a test drive and see if the noise was still there. His wheels are the 16" and have 205/60/R16 tires (also Defenders), while mine has the 15" rims and 195/65/R15.

First question: can this swap be done safely?

Second question: If not, what should I do to diagnose the source of the noise. It's loud, and I think it's getting louder (though maybe I'm just hearing it more now that I'm focused on it).

Aside: The same friend has a heat camera, so we took the car on the highway and then shot it at the hub area to see if one side got hotter than the other. They both stayed the same temp.

 

Hi Don, thanks for your reply. I had a friend in the car the other day who asked if I still had my snow tires on- the noise sounds like that. It has a tone that increases in pitch as I speed up. Definitely not a scraping or grinding sound. More of a RRRRRRRRRRR sound. I will try to record and post today.

 

The wheel bearing was my thought as well. Here's an audio recording where I get up to about 40 mph toward minute two: link.

I'm uploading a video right now (slow connection) where you can hear it very clearly. Will post when it's done.

 

Here's that video:

Since it sounds like the concensus is wheel bearing, I have two followup questions:

-Is $150 a reasonable quote for labor for the job?
-I see a huge range of prices on RockAuto. It seems like the Timken is the highest quality (and price) replacement. Has anyone had any luck with one of the less expensive options?

 

I don't want to risk the job with lower quality! Was just curious if the less expensive parts were truly lower quality. Why do you recommend doing both at the same time? And what do you think about the $150 quote in labor?