Indiana Code Title 9. Motor Vehicles § 9-19-5-3

Sec. 3. (a) Except as provided in subsection (b):

a siren, whistle, or bell.

(b) An authorized emergency vehicle may be equipped with a siren, whistle, or bell that is capable of emitting sound audible under normal conditions from a distance of not less than five hundred (500) feet and of a type approved by the department. A siren authorized under this section may not be used except when the vehicle is operated in response to an emergency call or in the immediate pursuit of an actual or suspected violation of the law. The person who drives a vehicle equipped with a siren under this section shall sound the siren when reasonably necessary to warn pedestrians and other persons who are driving vehicles of the approach of the authorized vehicle.