Wheel Bearing Sound??

Hey folks!

I have been searching online (and this site) as to how to determine when it's necessary to replace the wheel bearings (front). My 2004 with 280,xxx miles has been making noises at certain speeds that sound like the sound you hear if you have your window open and a Jeep passes you with off road tires. The best way to describe it is a howling sound. The sound starts presenting itself above 45 mph and is really loud when I start going about 70-75. Above 80 you really can't hear it. I am not certain if it is the tires I purchased around 15,000 miles ago. They are a new version of a Firestone all season tire. It's certainly plausible that the tires can be the issue, but it also is a possibility it is the wheel bearing(s). Any advice would be appreciated. As a safety measure, if it gets worse, I am going to my mechanic to have it looked at. TIA