40-6-14.
   
  (a) It is unlawful for any person operating or occupying a motor
  vehicle on a street or highway to operate or amplify the sound
  produced by a radio, tape player, or other mechanical sound-making
  device or instrument from within the motor vehicle so that the sound
  is plainly audible at a distance of 100 feet or more from the motor
  vehicle.
   
  (b) The provisions of this Code section shall not apply to any law
  enforcement motor vehicle equipped with any communication device
  necessary in the performance of law enforcement duties or to any
  emergency vehicle equipped with any communication device necessary
  in the performance of any emergency procedures.
   
  (c) The provisions of this Code section do not apply to motor
  vehicles used for business or political purposes, which in the
  normal course of conducting such business use sound-making devices.
  The provisions of this subsection shall not be deemed to prevent
  local authorities, with respect to streets and highways under their
  jurisdiction and within the reasonable exercise of the police power,
  from regulating the time and manner in which such business may be
  operated.
   
  (d) The provisions of this Code section do not apply to the noise
  made by a horn or other warning device required or permitted by Code
  Section 40-8-70. The Department of Public Safety shall promulgate
  rules defining "plainly audible" and establish standards regarding
  the measurement of sound by law enforcement personnel.
   
  (e) A violation of this Code section shall be a misdemeanor.