My left rear tire has been making this noise at speed for a while now and was hoping maybe the audio might ring some bells to some more savvy car repair gurus. I don't hear anything at all when moving more slowly, as far as I can tell, but from 20mph on, it usually starts showing itself. From what I can tell, it doesn't change when I turn. You can't really tell in the audio file, but the sound is more "whappy" when I've got the window down. I have no idea how to explain it, but the sound of my treads on the pavement seems to magnify when the sound is happening and I'm moving slowly.

You can check the audio out [here] for what it sounds like on a particularly bad day (for some reason, it gets better or worse and I can't figure out why - it's usually nowhere near this bad): (https://drive.google.com/file/d/0B0P9KYrJetNoTXlHbEpwc0ZVcUE/view).

It's not really a constant noise, as much as a "whap whap" noise, like there's a flat bit on my tire or something, but I've got no clue.

I was nervous it was a wheel bearing, even though the noise didn't really match up to what I found online, so I jacked up my car and spun both of my rear tires - nothing. They both spun smooth, no catches, and there was no play in any direction in either of them. Although that could mean nothing, considering I know so little.

Figure my next step is taking it into a shop, but I wanted to bring it here in case it might be something stupid I could fix myself or something that isn't going to end with my wheel flying off.