At what distance is a motor vehicle noise violation considered plainly audible?

• A. 10 ft
• B. 25 ft
• C. 50 ft
• D. 100 ft

Answer: (B)

Plainly audible is measured as the noise being clearly heard by an average person at a specific distance from the vehicle. The idea is to objectify enforcement: if the sound is distinctly audible at a moderate distance, it’s considered excessive for a motor vehicle. Twenty-five feet hits a practical middle ground—far enough that typical street background noise can be accounted for, yet close enough for an officer to observe without being unreasonably near or depending on guesswork about how loud the sound is. At only ten feet, judgments become very dependent on the moment and the observer’s ears; at fifty or a hundred feet, ambient traffic, wind, and other noises could make normal sounds seem louder or quieter than they are, leading to unreliable enforcement. So the standard distance used is twenty-five feet.