(a)   The Mayor is hereby authorized, where it is necessary to preserve health, to establish zones of quiet.  Whenever authorized signs are erected indicating a zone of quiet, no person operating a motor vehicle within any such zone shall sound the horn or other warning device of such vehicle except in an emergency.
   (b)   For the purpose of protecting the welfare of the patients of the Elyria Memorial Hospital, the portions of East River Street lying between Princeton Avenue on the south and Broad Street on the north, are declared to be zones of quiet.  No person while within the zones of quiet shall make any unnecessary noise that will probably be heard at the main building of the Elyria Memorial Hospital.
(R.O. 1946, C.20, Sec. 39.)