531.01   DEFINITIONS.
   As used in this chapter, certain terms are defined as follows:
   (1)   "A-weighted sound level" means the sound pressure level in decibels, as measured on a sound level meter using the A-weighting network. The level  so read is designated dB or dBA.
   (2)   "Commercial area" means any B-1, B-2, B-3, B-4 or B-5 District as set forth in the Zoning Code.
   (3)   "Construction" means any site preparation, assembly, erection, substantial repair, alteration or similar action, but excluding demolition, for or on a public or private right-of-way, structure, utility or similar property.
   (4)   "Cyclically varying noise" means any sound which varies in sound level such that the same level is obtained repetitively at reasonably uniform intervals of time.
   (5)   "Decibel" means a unit for measuring the volume of sound, equal to twenty times the logarithm to the base ten of the ratio of the pressure of the sound measured to the reference pressure, which is twenty micropascals (twenty micronewtons per square meter).
   (6)   "Demolition" means any dismantling or intentional destruction or removal of structures, utilities, public or private right-of-way surfaces or similar property.
   (7)   "Emergency" means any occurrence or set of circumstances involving actual or imminent physical trauma or property damage or loss which demands immediate action.
   (8)   "Emergency work" means any work performed for the purpose of preventing or alleviating the physical trauma or property damage threatened or caused by an emergency.
   (9)   "Gross vehicle weight rating" means the value specified by the manufacturer as the recommended maximum loaded weight of a single motor vehicle. In cases where trailers and tractors are separable, the gross combination weight rating (GCWR), which is the value specified by the manufacturer as the maximum loaded weight of the combination vehicle, shall be used.
   (10)   "Impulsive sound" means a sound of short duration, usually less than one second, with an abrupt onset and rapid decay. Examples of sources of impulsive sound include explosions, drop forge impacts, and the discharge of firearms.
   (11)   "Motor vehicle" means every vehicle defined as a motor vehicle in the Traffic Code.
   (12)   "Motorcycle" means every vehicle defined as a motorcycle in the Traffic Code.
   (13)   "Motorized bicycle" means every vehicle defined as a motorized bicycle in the Traffic Code.
   (14)   "Noise" means any sound which annoys or disturbs humans or which causes or tends to cause an adverse psychological or physiological effect on humans.
   (15)   "Noise disturbance" means any sound which endangers or injures the safety or health of humans or animals; annoys or disturbs a reasonable person of normal sensitivities; or endangers or injures personal or real property.
   (16)   "Person" means any individual, association, partnership or corporation and includes any officer, employee, department, agency or instrumentality of a state or any political subdivision of a state.
   (17)   "Place of public entertainment" means any commercial facility open to the general public for purposes of entertainment.
   (18)   "Powered model vehicle" means any self-propelled airborne, waterborne or landborne plane, vessel or vehicle, which is not designed to carry persons, including, but not limited to, any model airplane, boat, car or rocket.
   (19)   "Public right-of-way" means any street, avenue, boulevard, highway, sidewalk, alley or similar place which is owned or controlled by a governmental entity.
   (20)   "Pure tone" means any sound which can be distinctly heard as a single pitch or set of single pitches. For the purposes of measurement, a pure tone shall exist of the one-third octave band sound pressure level in the band when the tone exceeds the arithmetic average of the sound pressure levels of the two contiguous one-third octave bands by five dB for frequencies of 500Hz and above, by eight dB for frequencies between sixteen and 400Hz, and by fifteen dB for frequencies less than or equal to 125Hz.
   (21)   "Real property boundary" means an imaginary line along the ground surface, and its vertical extension, which separates the real property owned by one person from that owned by another person, but not including intrabuilding real property divisions.
   (22)   "Receiving property" means any property which is affected by sound originating at another location.
   (23)   "Repetitive impulsive noise" means any noise which is composed of impulsive noises that are repeated at sufficiently slow rates such that a sound level meter set at "fast" meter characteristic will show changes in sound.
   (24)   "Residential area" means one-family, two-family, and multi-family districts.
   (25)   "Sound" means an oscillation in pressure, particle displacement, particle velocity or other physical parameter, in a medium with internal or interval forces that cause compression and rarefaction on that medium, and which propagates at finite speed to distant points. The description of sound may include any characteristic of such sound, including duration, intensity and frequency.
   (26)   "Sound level" means the weighted sound pressure level obtained by the use of a sound level meter and frequency weighting network, such as A, B or C as specified in American National Standards Institute specifications for sound level meters, Publication 51.4-1971, or the latest approved revision thereof. If the frequency weighting employed is not indicated, the A- weighting shall apply.
   (27)   "Sound level meter" means an instrument, including a microphone, amplifier, RMS detector and integrator, time averager, output meter and/or visual display and weighting networks, that is sensitive to pressure fluctuations. The instrument reads sound pressure level when properly calibrated and is of type two or better as specified in American National Standards Institute Publication 51.4-1971 or the latest approved revision thereof.
   (28)   "Sound pressure" means the instantaneous difference between the actual pressure and the average or barometric pressure at a given point in space as produced by sound energy.
   (29)   "Sound pressure level" means twenty times the logarithm of twenty micropascals (20 x 106 N/m2). The sound pressure level is denoted Lp or SPL and is expressed in decibels.
(Ord. A-1846.  Passed 3-23-92.)