NOISY door locks

Hello! The door locks on my 2000 Chrysler 300M have recently been making a LOT of noise. It started with the front passenger door lock, and about a week later it was both front locks. When the doors lock and unlock, they make a horribly loud buzzing-type of noise. People have actually turned their heads to see what the noise was! Any help on this would be much appreciated! Thanks, Julie