A person commits the offense of causing unreasonable sound amplification from a vehicle if the person operates, or permits the operation of, any sound amplification system which is plainly audible outside of a vehicle from 50 or more feet when the vehicle is on a public highway or on premises open to the public, unless that system is being operated to request assistance or warn of a hazardous situation.
Subsection (1) of this section does not apply to:
Vehicles being operated outside of an urban growth boundary;
Sound systems of vehicles used for advertising, or in parades, political or other special events, except that the use of sound systems on those vehicles may be prohibited by a local authority by ordinance or resolution;
Audio alarm systems installed in vehicles; or
Federal Communications Commission licensed two-way radio communications systems.
As used in subsection (1) of this section, “plainly audible” means any sound for which the information content of that sound is unambiguously communicated to the listener including, but not limited to, understandable spoken speech, comprehension of whether a voice is raised or normal or comprehensible musical rhythms or vocal sounds.