A. All terminology used in this chapter and not defined below shall be interpreted in conformance with applicable American National Standards Institute publications, including, but not limited to, Sl. 1-1960, R 1971, or those from its successor publications or bodies.
B. For the purposes of this chapter, certain words and phrases used herein are defined as follows:
A-WEIGHTED SOUND PRESSURE LEVEL: The sound pressure level as measured with a sound level meter using the A-weighting network. The standard notation is "dB(A)" or "dBA".
AMBIENT SOUND PRESSURE LEVEL: The sound pressure level of the all encompassing noise associated with a given environment, usually a composite of sounds from many sources. It is also the A-weighted sound pressure level exceeded ninety percent (90%) of the time based on a measurement period which shall not be less than ten (10) minutes.
CONTINUOUS SOUND: Any sound which exists, essentially without interruption, for a period of ten (10) minutes or more.
CYCLICALLY VARYING NOISE: Any sound which varies in sound level such that the same level is obtained repetitively at reasonably uniform intervals of time.
DECIBEL: A logarithmic and dimensionless unit of measure often used in describing the amplitude of sound. Decibel is denoted as "dB".
DEVICE: Any mechanism which is intended to produce, or which actually produces, noise when operated or handled.
DYNAMIC BRAKING DEVICE (Commonly Referred To As JACOB'S BRAKE): A device used primarily on trucks for the conversions of the engine from an internal combustion engine to an air compressor for the purpose of braking without the use of wheel brakes.
EMERGENCY VEHICLE: A motor vehicle used in response to a public calamity or to protect persons or property from an imminent exposure to danger.
EMERGENCY WORK: Work made necessary to restore property to a safe condition following a public calamity, or work required to protect persons or property from an imminent exposure to danger.
IMPULSIVE NOISE: A noise containing excursions usually less than one second, or sound pressure level using the fast meter characteristic.
MOTOR VEHICLE: Any vehicle which is self-propelled by mechanical power, including, but not limited to, passenger cars, trucks, truck trailers, semitrailers, campers, motorcycles, minibikes, go-carts, snowmobiles and racing vehicles.
MUFFLER: An apparatus consisting of a series of chambers or baffle plates designed for the purpose of transmitting gases while reducing sound emanating from such apparatus.
NINETIETH PERCENTILE NOISE LEVEL: The A-weighted sound pressure level that is exceeded ninety percent (90%) of the time in any measurement period (such as the level that is exceeded for 9 minutes in a 10 minute period) and is denoted "L90".
NOISE: Any sound which is unwanted or which causes or tends to cause an adverse psychological or physiological effect on human beings.
NOISE DISTURBANCE: Any sound which annoys or disturbs reasonable persons with normal sensitivities, or which injures or endangers the comfort, repose, health, hearing, peace and safety of other persons.
PERCENTILE SOUND PRESSURE LEVEL: Tenth percentile noise level; the A-weighted sound pressure level that is exceeded ten percent (10%) of the time in any measurement period (such as the level that is exceeded for 1 minute in a 10 minute period) and is denoted "L10".
PERSON: Any human being, firm, association, organization, partnership, business, trust, corporation, company, contractor, supplier, installer, user, owner or operator, including any municipal corporation or its officers or employees.
PLAINLY AUDIBLE NOISE: Any noise for which the information content of that noise is unambiguously transferred to the listener, such as, but not limited to, understanding of spoken speech, comprehension of whether a voice is raised or normal, or comprehension of musical rhythms.
PROPERTY BOUNDARY: An imaginary line exterior to any enclosed structure, at the ground surface, and its vertical extension, which separates the real property owned by one person from that owned by another person.
PUBLIC RIGHT OF WAY: Any street, avenue, boulevard, highway or alley, or similar place, which is owned or controlled by a public governmental entity.
PURE TONE: Any sound which 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 (1/3) octave band sound pressure level in the band with the tone exceeds the arithmetic average of the sound pressure levels of the two (2) contiguous one-third (1/3) octave bands by five (5) dB for frequencies of five hundred (500) Hz and above, by eight (8) dB for frequencies between one hundred sixty (160) and four hundred (400) Hz, and by fifteen (15) dB for frequencies less than or equal to one hundred twenty five (125) Hz.
REPETITIVE IMPULSIVE NOISE: Any noise which is composed of impulsive noises that are repeated at sufficiently slow rates such that a sound level meter set at the "fast" meter characteristic will show changes in sound pressure level greater than ten (10) dBA.
SOUND: A temporal and spatial oscillation in pressure, or other physical quantity, in a medium with interval forces that causes compression and rarefaction of that medium, and which propagates at finite speed to distant points.
SOUND LEVEL METER: An instrument, including a microphone, amplifier, RMS detector and intergrator, time averager, output meter and/or visual display and weighing networks, that is sensitive to pressure fluctuations. The instrument reads sound pressure level when properly calibrated and is of type 2 or better as specified in American National Standards Institute publication SL. 4-1971 or its successor publication.
SOUND PRESSURE: The instantaneous difference between the actual pressure and the average or barometric pressure at a given point in space due to sound.
SOUND PRESSURE LEVEL: Twenty (20) times the logarithm to the base-10 of the ratio of the RMS sound pressure to the reference pressure, which shall be twenty (20) micropascals, denoted LP or SPL.
STATIONARY NOISE SOURCE: Any device, fixed or movable, which is located or used on property other than a public right of way.
STEADY NOISE: A sound pressure level which remains essentially constant during the period of observation, i.e., does not vary more than six (6) dBA when measured with the "slow" meter characteristic of a sound level meter.
USE DISTRICT: Those districts established by the city zoning ordinance set out at title 21A of this code, as amended, or its successor title. (Prior code § 18-33-2)