My launch Verizon matte black 7 plus had the noise coming from the back and was audible in video recordings.  I received a replacement shortly after launch, only to have the same thing.  A co-worker had the gloss black AT&T 7 plus that didn't have any noise.  So, I lived with this until I recently picked up the new Red Verizon 7 Plus and I hear noting from the back.  Seems like they resolved this issue.  I don't know if it is coincidence, but the new phone feels more responsive than my original 7 plus and I always seemed to have issues with raise to wake on my old one, but the new one is working flawlessly.  I was always one to get the iPhone on launch day, but now I am starting to think it may be better to wait.  I may wait out this years release until they work out any issues.