Definitions. All terminology used in this chapter and not defined below shall be in conformance with applicable publications of the American National Standards Institute (ANSI) or its successor body. As used in this chapter, the following terms shall have the meanings indicated herein:
AMBIENT SOUND LEVELThe composite or normal or existing sound from all sources measured at a given location for a specific time of the day or night.
CYCLICALLY VARYING NOISESteady, fluctuating or impulsive noise which may or may not contain a pure tone and which varies in sound pressure level such that the same level is obtained repetitively at reasonably uniform intervals of time.
DECIBELThe logarithmic and dimensionless unit of measurement often used in describing the loudness of sound. Decibel is denoted as dB.
DEVICEAny mechanism which is intended to produce, or which actually produces, noise when operated or handled.
EMERGENCY WORKWork 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.
EMERGENCY VEHICLEA motor vehicle used in response to a public calamity, or to protect persons or property from an imminent exposure to danger.
IMPULSIVE NOISEA noise characterized by brief excursions of sound pressure whose peak levels exceed the ambience by 10dB. The duration of a single impulse is usually less than one second and requires the use of a sound level meter specially adapted for its measurement. Examples of impulsive sound include but are not limited to gun shots, blasting and hammering.
MOTOR VEHICLEAny vehicle which is self-propelled by mechanical power, or propelled by human power or electric power from overhead wires or electrified rails, including, but not limited to, passenger cars, trucks, trucktrailers, trains, semi-trailers, campers, motorcycles, minibikes, go-carts, snowmobiles and racing vehicles.
NOISEAny sound which annoys or disturbs humans or which causes or tends to cause an adverse psychological or physiological effect on human, or which endangers personal or real property.
PLAINLY AUDIBLE NOISEAny 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.
PURE TONEAny sound which can be distinctly heard as a single pitch or a set of single pitches. For the purposes of this chapter, a pure tone shall exist if the 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 contiguous 1/3 octave bands by five dB for center frequencies of 500 Hz and above, by eight dB for center frequencies between 160 Hz and 400 Hz and by 15 dB for center frequencies less than or equal to 125 Hz.
SOUNDA temporal and spatial oscillation in pressure, or other physical quantity, in a medium with internal forces that causes compression and rarefaction of 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.
SOUND LEVELThe 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 (ANSI SI.4-1983), or the latest approved revision thereof. If the frequency weighting employed is not indicated, the A-weighting shall apply (dBA).
SOUND LEVEL METERAn 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. The sound level meter used for testing purposes in accordance with this chapter shall meet the current American National Standard Institute specifications.
SOUND PRESSUREThe instantaneous difference between the actual pressure and the average or barometric pressure at a given point in space due to sound.
STATIONARY NOISE SOURCEAny device, fixed or movable, which is located or is being used on geographically defined real property other than a public right-of-way.