(a) (1) Every motor vehicle when operated upon a highway shall be equipped with a horn which is in good working order and capable of emitting sound audible, under normal conditions, from a distance of not less than 200 feet.
(2) No motor vehicle shall be equipped with, nor shall any person use upon a vehicle, any siren, whistle, or bell. Any vehicle may be equipped with a theft alarm signal device which shall be so arranged that it cannot be used as an ordinary warning signal. Every emergency vehicle shall be equipped with a siren, whistle or bell, capable of emitting sound audible under normal conditions from a distance of not less than 500 feet and of a type approved by the Director of Public Safety. Such equipment shall not be used except when such vehicle is operated in response to an emergency call or is in the immediate pursuit of an actual or suspected violator of the law, in which case the driver of the emergency vehicle shall sound such equipment when it is necessary to warn pedestrians and other drivers of the approach thereof.
(ORC 4513.21)
(b) No person shall use the horn of a motor vehicle except to give warning to other drivers or pedestrians.