§ 38-67. Definitions.
The following words, terms and phrases, when used in this article, shall have the meanings ascribed to them in this section, except where the context clearly indicates a different meaning. All terminology used in this article, not specifically defined, shall be in conformance with applicable publications of the American National Standards Institute (ANSI) or its successor body.
Agricultural means the land uses where agricultural activities are legally permitted.
A-weighted sound level means the sound pressure level in decibels as measured on a sound level meter using the A-weighted network. The level so read is designated dBA.
Commercial means the land uses where retail sales and services, professional, tourist and other commercial activities are legally permitted.
Construction means any site preparation, assembly, erection, substantial repair, alteration or similar action, but excluding demolition, for or on public or private rights-of-way, structures, utilities or similar property.
Daylight hours means one-half hour before sunrise and one-half hour after sunset.
Decibel (dB) means a unit for describing the amplitude of sound, equal to 20 times the logarithm to the base 10 of the ratio of the pressure of the sound measured to the reference pressure, which is 20 micronewtons per square meter.
Emergency work means any work performed for the purpose of preventing or alleviating physical trauma or property damage threatened or caused by an existing or imminent peril.
Environmental control officer means the director of the city environmental control division.
Noise means any sound that annoys or disturbs humans or causes or tends to cause an adverse psychological or physiological effect on humans. The term is used synonymously with the term "sound."
Noise disturbance and sound disturbance means any sound in quantities that are or may be potentially harmful or injurious to human health or welfare, animal or plant life or property, or unnecessarily interfere with the enjoyment of life or property, including outdoor recreation, of a reasonable person with normal sensitivities.
Pure tone means any sound that can be distinctly heard as a single pitch or a set of single pitches. For the purposes of measurement, a pure tone shall exist if the one-third octave band sound pressure level in the band with the tone exceeds the arithmetic average of the sound pressure levels of the two contiguous one-third octave bands by five decibels for center frequencies of 500 H z and above, and by eight decibels for center frequencies between 160 and 400 H z , and by 15 decibels for center frequencies less than or equal to 125 H z .
Real property line means an imaginary line along the surface, and its vertical plane extension, which separates the real property owned, rented or leased by one person from that owned, rented or leased by another person, excluding intrabuilding real property divisions.
RMS (root mean square) means the square root of the mean of a set of squared values.
Sound means an oscillation in pressure, stress, particle displacement, particle velocity or other physical parameter, in a medium with internal forces. The description of sound may include any characteristic of such sound, including duration, intensity and frequency. The term is used synonymously with the term "noise."
Sound level means the weighted sound pressure level obtained by the use of a metering characteristic and weighting A, B or C as specified in American National Standards Institute specifications for sound level meters, ANSI S1.4-1971, or in successor publications. If the weighting employed is not indicated, the A-weighting shall apply.
Sound level meter means an instrument that includes a microphone, amplifier, RMS detector, integrator or time averager, output meter and weighting networks used to measure sound pressure levels. The output meter reads sound pressure level when properly calibrated, and the instrument is of type 2 or better, as specified in the American National Standards Institute publication S1.4-1971, or its successor publications.
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 the presence of sound energy.
Sound pressure level means 20 times the logarithm to the base 10 at the ratio of the RMS sound pressure to the reference pressure of 20 micropascals (20 × 10 -6 N/m ). The sound pressure level is denoted L p or SPL and is expressed in decibels.
Special variance and variance mean an authorization, issued by the city manager or his duly authorized representative, to exceed the sound level limit for a specified period of time.
(Ord. No. 96-15, § I(50-491), 3-4-1996)
Cross reference
Definitions generally, § 1-2.