It shall be unlawful for any person to make, continue, allow or cause to be made or emanate any excessively, unnecessarily, unnaturally or unusually loud noise or sound from any radio, phonograph, disc player, tape deck, stereo, television or other mechanical, electrical or electronic sound amplification device or instrument which annoys, disturbs, injures or endangers the comfort, repose, quiet, health, peace or safety of other persons within the city; such act or acts hereby being declared a public nuisance. In interpreting and applying this section, the following shall apply:
A. Emanating noise or sound shall be defined for these purposes as "excessively", "unnecessarily", "unnaturally" or "unusually loud" when it is plainly audible to a person of normal hearing sensitivity at a distance of twenty five feet (25') from the source of such noise or sound. Proof of same shall be prima facie evidence of a violation of this section.
B. Prima facie evidence that such noise or sound annoys, disturbs, injures or endangers the comfort, repose, quiet, health, peace or safety of other persons is shown by proof of subsections A and E of this section, or a complaint by a person or persons regarding such noise or sound.
C. A person of normal hearing sensitivity for these purposes is a person who has a hearing threshold level of between zero (0) decibels and twenty five (25) decibels HL averaged over the frequencies five hundred (500), one thousand (1,000) and two thousand (2,000) hertz.
D. The distance from the source of such noise or sound shall be measured from the actual source itself, except where the source is located on private property in which case the distance shall be measured from the property line.
E. Alternative prima facie evidence that such noise or sound is excessively, unnecessarily, unnaturally or unusually loud is shown by a sound level exceeding the ambient sound level by more than five (5) decibels measured at the property line or, in the case of common wall construction of condominiums, apartments or business facilities, measured within the adjoining occupied unit.
F. Nothing in this section prohibits or declares unlawful or a nuisance:
1. The operation of warning or amplification devices by emergency, fire or law enforcement vehicles or personnel;
2. Lawful use of vehicle horns or backup warning devices;
3. Private or public warning or alarm equipment or systems;
4. The conduct of previously authorized and otherwise lawful public activity such as parades, speeches, lectures, ceremonies, entertainment, sports, music or recreation events; or
5. The usual and customary operation of bells, gongs, buzzers or similar mechanical, electrical or electronic sound amplification devices to mark time or call to attendance for an otherwise lawful use or purpose. (Ord. 723, 6-20-1989)