Northern Territory Consolidated Regulations Northern Territory Consolidated Regulations(1) A motor vehicle must be fitted with at least 1 horn or other device that can give sufficient audible warning to other road users of the approach or position of the vehicle.
(2) A motor vehicle must not be fitted with a device that can make a sound like the sound of a siren, bell, exhaust whistle, compression whistle or repeater horn.
(3) However, subrule (2) does not apply to:
(a) a police vehicle; or
(b) an emergency vehicle; or
(c) a transport enforcement vehicle; or
(d) an Australian Protective Service vehicle; or
(e) a vehicle in the service of the Australian Border Force (as defined in section 4(1) of the Australian Border Force Act 2015 (Cth)); or
(f) an Airservices Australia vehicle; or
(g) a vehicle at least 25 years old that is fitted as a police or emergency vehicle if:
(i) the vehicle is used for exhibition purposes; or
(ii) it is part of a collection of former police or emergency vehicles; or
(h) an anti-theft alarm if the alarm cannot be operated while the vehicle's ignition is on.
(4) Also, a motor vehicle may be fitted with a device that emits a regular, intermittent sound while the vehicle is reversing or in reverse gear.
(5) The device must not be louder than is necessary so the driver, and a person near the vehicle, can hear the device when it is operating.