§ 13-6-2. Definitions.

For the purpose of this article, certain words and phrases used herein are defined as follows:

"A" Band Level. "A" band level is the total sound level of all noise as measured with a sound level meter using the "A" weighting network. The unit of measurement is the dB(A).

Acoustical Terminology. All technical definitions are in accordance with American Standard S1, 1-1960 entitled Acoustical Terminology.

Ambient Noise. Ambient noise is the all-encompassing noise associated with a given environment, being usually a composite of sounds, near and far.

"A" Use District. "A" Use Districts shall include RH, RD, RN, RS, RM, CVP, IS, and UT Zoning Districts as defined in the City of Concord's Zoning Ordinance.

Band Pressure Level. Band pressure level of sound for a specified frequency band is the sound pressure level for the sound contained within the restricted band. The reference must be specified.

Bel. Bel is a unit of level when the base of logarithm is ten (10). Use of Bel is restricted to levels of quantities proportional to power.

"B" Use District. "B" Use District shall include RO, CN, CG, CU, CBP, GWP, OCP, and OFP Zoning Districts as defined in the City of Concord's Zoning Ordinance.

"C" Use District. "C" Use District shall include the IN Zoning District as defined in the City of Concord's Zoning Ordinance.

Construction Activity. Any excavation, highway construction, land development or land clearing work, or the erection, demolition, alteration, repair, or relocation of any building or structure, which uses powered equipment such as backhoes, trucks, tractors, earth moving equipment, compressors, motorized, or power hand tools, manual tools, or equipment of a similar nature as well as two-way radios or other communication equipment.

Cycle. Cycle is the complete sequence of values of a periodic quantity that occur during a period.

Decibel. Decibel is one-tenth root of ten (10), and the quantities concerned are proportional to power.

Emergency Work. Emergency work is work made necessary to restore property to a safer condition following a public calamity to work required to protect persons or property from an imminent exposure to danger, or to provide electricity, water or other public utilities when public health or safety are involved.

Frequency. Frequency of a function periodic in time is the reciprocal of the primitive period. The unit is the cycle per unit time and must be specified.

Microbar. Microbar is a unit of pressure commonly used in acoustics and is equal to one dyne per square centimeter.

Period. Period of a periodic quantity is the smallest increment of time for which the function repeats itself.

Periodic Quantity. Periodic quantity is an oscillating quantity, the values of which recur for equal increments of time.

Sound Analyzer. Sound analyzer is a device for measuring the band pressure level or pressure spectrum level of a sound as a function of frequency.

Sound-Level Meter. Sound-level meter is an instrument including a microphone, an amplifier, and out-put meter, and frequency weighting networks for the measurement of noise and sound levels in a specified manner.

Sound Pressure Level. Sound pressure level in decibels, of sound is twenty (20) times the logarithm to the base ten (10) of the ratio of the pressure of this sound to the reference pressure which reference pressure must explicitly state.

Spectrum. Spectrum is a function of time and is a description of its resolution into components, each of different frequency and usually of different amplitude and phase and is also to signify continuous range of components each of different frequency and usually of different amplitude and phase and is also used to signify continuous range of components usually wide in extent which waves have some specified characteristics such as "audio-frequency spectrum" and is also applied to functions of variables other than time.

(Ord. No. 2604, §§ II—IV, 4-11-05)