Looking for a good resource/website to find environmental noise regulations at the state/county/city level, any suggestions other than those listed below?
Some municipalities have enacted noise restrictions. These would be detailed in the Municipal Code. I find many of the cities here in No Cal have the Code online. Useful if you are looking for a specific locale, not so much if you are looking for a global view.
Also, cities that have airports will have noise ordinances for aircraft.