Each area has sound ordinances. Ever hear of "disturbing the peace"? You must be a millenial.

 

Nice try, but no.

You must be even older as you read into my statement way further than it was written and can't spell millennial. According to @Steve83 "Local laws are irrelevant"

In reality, local laws are set and are what matter, it's DEQ (which is also local) that sets the limits, again, removing the muffler does not automatically make it sound like a rocket taking off, too many dependents, engine, way it's driven, local ordinances determining the way in which the sound level is measured etc.

 

Hope the guys installing train horns are reading this...

 

Train horns are perfectly legal on vehicles, just like guns & bottles of alcohol. Each can only be used legally under specific conditions, but it's legal to have them.