(a) Whenever authorized signs are erected indicating a zone of quiet, no person operating a vehicle within any such zone shall sound the horn or other warning device of such vehicle except in an emergency.
(b) Whoever violates this section is guilty of a minor misdemeanor on a first offense; on a second offense within one year after the first offense, the person is guilty of a misdemeanor of the fourth degree; on each subsequent offense within one year after the first offense, the person is guilty of a misdemeanor of the third degree.