Getting Rid of Matts

I have a Golden Retriever, very long hair, and he gets matts behind his ears. I check and check and there's nothing there, and then all of a sudden there's these huge matts pulling on the skin behind his ears. I use a comb with a razor in it to remove them because they're so close to the skin I'm afraid to use scissors. Does anyone know of an easier way? I can't use an electric razor because he freaks out at the sound.