337.26 MOTOR VEHICLE NOISE LIMITS.
   (a)   No person shall operate a motor vehicle or combination of vehicles of any description, other than an authorized emergency vehicle or a vehicle moving under a special permit, at any time or under any condition of grade, load, acceleration or deceleration in such a manner that the noise level of the entire unit exceeds the following noise limit for the category of motor vehicle within the speed limits specified in this section:
 
             Noise Limit (dB(A))
Type of Vehicle         35 MPH or less   Over 35 MPH
1.   Heavy trucks and buses
   (exceeding 6000 lbs. G.W.)      88         90
2.   Motorcycles            82         86
3.   All other motor vehicles      76         82
   (b)   The noise limits established in subsection (a) hereof shall be based on a distance of fifty feet from the center of the lane of travel within the speed limit specified in such subsection, and shall be measured by a sound level meter which meets the Type 1 requirements of the American National Standard Sl. 4-1971, Specification for Sound Level Meters. The Department of Public Safety may provide for measuring at distances closer than fifty feet from the center of the lane of travel, provided, however, in such event the measuring devices shall be so calibrated as to provide for measurements equivalent to the noise limit established by this section measured at fifty feet.
   (c)   The noise level measurement secured from a sound level meter meeting the requirements of subsection (b) hereof shall be admissible in evidence in any prosecution under subsection (a) hereof.
(Ord. 84-73. Passed 9-24-73.)
   (d)   Except as otherwise provided in this subsection, whoever violates this section is guilty of a minor misdemeanor. If, within one year of the offense, the offender previously has been convicted of or pleaded guilty to one predicate motor vehicle or traffic offense, whoever violates this section is guilty of a misdemeanor of the fourth degree. If, within one year of the offense, the offender previously has been convicted of two or more predicate motor vehicle or traffic offenses, whoever violates this section is guilty of a misdemeanor of the third degree.