My New Iphone 5 Lifeproof Case Makes Loud Vibrating Sound?

My new Lifeproof case for my iPhone 5 came in yesterday, and I put it on and initially had no problems with the sound. Today, however, it started making an EXTREMELY annoying buzzing sound whenever anything plays on the speakers. It seems like the phone is vibrating against the case and that is what is making this noise, but I can’t figure out how to get it to stop. I tried taking out the phone and then placing it back in the case, but the problem still persists. Has anyone had a problem like this with a Lifeproof case before or have any idea what I can do to get it to stop? Thanks :)