Delaware Code
Subchapter I. Equipment Requirements
§ 4307. Warning devices for emergency vehicles.

(a) Every police, fire department and fire patrol vehicle and every ambulance used for emergency calls, except as provided in subsection (b) of this section, shall be equipped with a bell, siren or exhaust whistle.
(b) A vehicle used by a fire chief, deputy fire chief, assistant fire chief, or fire police officer of a duly organized fire department, which is not owned by or the property of the fire department, shall not be equipped with such warning devices.