Boone County, IN Noise Ordinances: Vehicle Noise (2026)

Boone County Code § 92.03(B)(3), part of Ord. 2007-14 (passed 7-16-2007), makes it unlawful to discharge exhaust noise into the open air from an internal combustion engine or any engine or power unit on a motorcycle, other motor vehicle, or craft of any kind, unless the noise passes through a muffler or other device that effectively reduces and prevents it. Farm vehicles are carved out of that muffler mandate entirely. Separately, the section imposes a standing equipment duty: a motor vehicle must be equipped with a muffler or other noise dissipation device that is both in good working order and in constant operation, so a driver cannot simply remove or bypass a muffler even briefly to avoid the noise standard.

The provision is one of the enumerated unlawful noises under § 92.03(B) and sits beneath the chapter's general ban on noise that is unreasonably loud or an obstruction to the free use of property (§ 92.03(A)). The Boone County Sheriff's Office enforces the chapter, and § 92.06 authorizes deputies to inspect a vehicle or its exhaust system on probable cause that a violation has occurred, seeking a county court warrant if access is refused. Under § 92.99, a verbal warning precedes any citation; a continuing violation after the warning can draw a court-set fine of up to $250, or $100 if paid at least seven days before the hearing. The agricultural-noise exemption in § 92.05 covers farm equipment generally, reinforcing why farm vehicles are excluded from the muffler requirement in this section.