I've noticed that at times it will be very loud and at other times it is only barely heard. I can only notice it at very low speeds. 1-2mph, when the brake is applied lightly it goes away. Obviously I feel that it is brake related. I pulled the wheel off and visually inspected the entire rotor and it seems fine. Any ideas?

 

To me it sounds like one of the brake pad rattle clips is missing alowing the pad to move up and down. But this noise would not normally be loud. I would disasemble the front brakes, make sure all the pad retainer clips are there. Then pull the rotor and check the hub/bearing assembly, spin it and see what it sounds like. It should spin silently, if it clicks or makes a sound like the bearings are dry it's bad.

 

I had the same problem last summer. The brake pad was rattleing in the caliper. I think I just bent the rattle clips out to hold the pad tighter in the caliper. Once I found where it was coming from it was easy to fix. When I was driving next to a wall on the right side it was a lot louder cause the sound was bouncing off the wall and back toward me, I think. Good luck