I rarely ever hear a ringing, but it does happen sometimes. I heard a loud ringing last night, though, when attempting to WILD within a dream. :O

Sometimes I hear a noise before the vibrating, sometimes I hear a rushing noise during the vibrating, but sometimes no noise at all. I've only succeeded at WILDing once, and that time I heard all sorts of noises as I entered a lucid dream, as I watched and listened to a world being formed around me. I hope it happens again some day.