South Australian Numbered Regulations South Australian Numbered Regulations(1) In this rule—
"repeater horn" means a device that makes a sound alternating between different tones or frequencies on a regular time cycle.
(2) 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.
(3) A motor vehicle must not be fitted with a device that can make a sound like the sound of a siren, exhaust whistle, compression whistle or repeater horn.
(4) However, subrule (3) does not apply to—
(a) an exempt vehicle; or
(aa) a vehicle at least 25 years old and fitted as an emergency vehicle or police vehicle if the vehicle—
(i) is used only for exhibition purposes; or
(ii) is part of a collection of former emergency vehicles or police vehicles; or
(b) an anti-theft alarm if the alarm cannot be operated while the vehicle’s ignition is on.
(5) 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.
(6) 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.
(7) The provision of the relevant ADR that corresponds to subrule (3) applies to a vehicle as if that provision did not contain a reference to a bell.