A couple of days ago I started hearing a noise coming from what sounds like outside my driver-side window. At first I wasn't sure it was coming from my car, but it definitely is.

It's difficult to characterize the noise. It sounds like the worlds smallest outboard motor floating somewhere in the front left quadrant of the car. It's not very loud, kind of medium pitched, but you can definitely hear it when driving above 60 mph or so.

Could this be a wheel bearing problem? Will probably take it to the shop soon, but just wondered if anyone can chime in. Thanks.

 

If its a wheel bearing it will change pitch as the car's speed changes.
My failed rear bearing made noise at all speeds.

My windshield rubber exterior molding split one time and a 8" piece of thin rubber "buzzed" in the wind above certain speeds.
It took me a few days to figure out what it was.

 

Left bearing noise could be the a failing propellor shaft. It was almost like a whistle at first. I would also check your left side mirror to make are that it's tight too. Mine was loose on right site and was shaking at only certain higher speeds but I don't recall making a loud noise. To tighten mirror house, just move mirror to one side and you can stick a Philips screw driver to righten the screws inside housing.

 

Well, went in to the shop and they said yep I had a noisy wheel bearing. Seems like the culprit. Will update if it turns out to be a misdiagnosis.