(a) A motor vehicle shall be equipped with a horn in good working condition that emits a sound audible under normal conditions at a distance of at least 200 feet.
(b) A vehicle may not be equipped with and a person may not use on a vehicle a siren, whistle, or bell unless the vehicle is:
(1) a commercial vehicle that is equipped with a theft alarm signal device arranged so that the device cannot be used as an ordinary warning signal; or
(2) an authorized emergency vehicle that is equipped with a siren, whistle, or bell that complies with Section 547.702.
(c) A motor vehicle operator shall use a horn to provide audible warning only when necessary to insure safe operation.
(d) A warning device, including a horn, may not emit an unreasonably loud or harsh sound or a whistle.