OAR 735-110-0050
Siren Mounting
(1)
Installation of sirens and speakers on authorized emergency vehicles shall be as follows:(a)
Class A electromechanical and mechanical sirens shall be mounted outside of the vehicle or, between the grille and radiator, or under the hood;(b)
Class B electromechanical and mechanical sirens shall be mounted outside of the vehicle, or between the grille and the radiator;(c)
Class A and B electronic sirens shall be mounted outside of the vehicle or with the horn opening facing forward ahead of the radiator with a relatively open path for the sound to project forward. The horn axis shall be parallel to the vehicle centerline;(d)
Dual speakers for electronic sirens shall be connected in phase and mounted so that the speaker axis is parallel to the vehicle centerline or angled outward not more than ten degrees to the sides;(e)
Electronic siren speakers may be mounted facing forward behind a speaker grille in a lightbar.(2)
Ambulances regulated by the Health Services are also subject to requirements of that agency. This includes the requirements for a Siren-Public Address System, Part 3.14.6 of KKK-A-1822B, the federal specifications for the “Star-of-Life Ambulance.”(3)
Mechanical motorcycle sirens that do not operate when the vehicle is stationary shall not be installed on motorcycles manufactured after January 1, 1981.
Source:
Rule 735-110-0050 — Siren Mounting, https://secure.sos.state.or.us/oard/view.action?ruleNumber=735-110-0050.