My wife recently spun out and hit a snow berm. There was no damage to the body and it appears that the left rear tire took the majority of the impact. The tire ended up going flat and we threw on a full size spare. Over the next couple days we noticed a humming/vibrating sound that only happens between 57mph to 63mph or so. There's nothing out of the ordinary outside of that window. The original tire ended up taking air fine and did not appear damaged. We were concerned about it and knew we needed new tires and an alignment before the accident. So we got an alignment done with some new tires. The alignment showed the left rear tire as "red" and required adjusting which made sense to us. However, the sound is still there even with the new tires and the alignment. The car drives smoothly and doesn't vibrate or anything. It's just a pulsing humming sound. You can hear it over a quiet radio and can carry on a conversation over the sound rather easily. It goes away completely if you aren't driving between 57mph and 63mph. Any thoughts?

The left rear wheel bearing was likely damaged. They are easy to replace. The procedure will be similar to the write-up below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-9.html#post1653648

Check prices online--Amazon.com tends to have great prices on Timken wheel bearing/hubs. It definitely sounds like a bad bearing, to me.

What I read about wheel bearing said that it normally gets louder and louder as you drive faster. Is that wrong? I didn't know if it would be the bearing since it goes away if you aren't driving at 60 mph.

How much should this cost if I get a local shop to do this for me? I'm in the MD/DC/VA area.

Some bearings only make noise when there is lateral pressure placed on them. At 60 mph, turn slightly to the left and then back again. This should increase the pressure on the left bearing and the noise should get louder.

Double-check my quick search, but Amazon.com has a new Timken Axle Bearing and Hub Assembly (Part No. 512009) for $54.02. I'd buy the part online, as I've done many times, and find someone local to install it. Call around for the best price. Many outfits, in Texas, will just charge for labor. The job should only take 30 minutes, or less.

Here's what the bearing looks like and costs:

http://www.stockwiseauto.com/Timken-512009-Axle-Bearing-and-Hub/M/B000BZABK8.htm

I'm in total agreement with TX. It's definitely the bearing. On your 98 Camry, the hub, flange, and bearing are all incased. Even comes with new wheel studs. I'm pretty sure this is a dealer only part and it's around 300 plus 1.5hr in labor.

Looks something like this, however, I wouldn't buy used.
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dautomotive&field-keywords=Toyota+bearings&x=0&y=0

Before replacing the bearing/hub, find out the rear spindle nut torque specification. It appears to be 90 lb.-ft. according to what I could find:

http://www.autowaresgroup.com/resources/documents/spindle_nut_torque_specs.pdf

I don't know what Camry model you have and whether you have ABS or not. Specify in the write-up how much it should be torqued. Make sure they do not install the bearing with an impact wrench.