Yes brakes do make noise when they wear down. theyre made to do that i believe. i just replaced mine.
Back on topic, i had this happen to me but it was only from the right side. turned out i had a bad bearing. if thats the case get it fixed because your tires will wear quickly with a bad one.

 

Yup, definitely a bearing. As Mad-Machine said, check the tire pressure to make sure they are not under inflated. But humming almost always indicates bearing problems, it is fairly loud and may sound like it's coming from both sides. I'll be very surprised if it's not a bearing.

 

ok thanks alot, at one point in time it sounded like it was comming from just the front right but now seems likes its comming from both sides. Im not sure if thats just because it got louder or if its happening to both sides, either way im going to have it fixed and i'll let you guys know what it was