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 technical terminology not defined in this article shall be interpreted in conformance with applicable American National Standards Institute noise specifications.
A-weighted sound pressure level.The sound pressure level in decibels as measured on a sound level meter using the A-weighing network. The level so read shall be designed dBA.
Ambient sound level.The sound level of the all-encompassing sound associated with a given environment, being usually a composite of sounds from many sources. It is also the A-weighted sound level exceeded 90 percent of the time, based on a measurement period that shall not be less than ten minutes or more than 30.
Decibel.A logarithmic unit of measure used in describing the amplitude of sound, denoted as dB.
Device.Any mechanism that is intended to produce, or which actually produces, noise when operated or handled.
Director.The director of planning and environmental services for the town.
Emergency work.Work made necessary to restore property to a safe condition following a public calamity, work to restore public utilities, or work required to protect persons or property from an imminent danger.
Motor vehicle.Any vehicle propelled by mechanical power, such as, but not limited to, any passenger car, truck, truck-trailer, semitrailer, camper, motorcycle, minibike, go-cart, dune buggy, or racing vehicle.
Muffler.Any apparatus consisting of baffles, chambers, or acoustical absorbing material whose primary purpose is to transmit liquids or gases while causing a significant reduction in sound emission.
Noise.Any sound that is unwanted or which causes, or tends to cause, an adverse psychological effect on human beings.
Percentile sound pressure level.(1) Ninetieth percentile level.The A-weighted sound pressure level that is exceeded 90 percent of the time in any measurement period (such as the level that is exceeded for nine minutes in a ten-minute period).
(2) Tenth percentile level.The A-weighted sound pressure level that is exceeded ten percent of the time in any measurement period (such as the level that is exceeded for one minute in a ten-minute period).
Person.Any individual, firm, association, partnership, corporation, or any other entity, public or private.
Property boundary.An imaginary line at the ground surface and its vertical extension that separates the real property owned or occupied by one person from that owned or occupied by another person.
Sound.A temporal or 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.
Sound level.The weighted sound pressure level measured by the use of a metering characteristic and weighted as specified in the American National Standards Institute specifications. The sound pressure level of a sound expressed in decibels is 20 times the logarithm to the base ten of the ratio of the pressure of the sound to the reference sound pressure of 20 micropascals. If the frequency weighting employed is not indicated, the A-weighting shall apply.
Sound level meter.An instrument, which includes a microphone, amplifier, RMS detector and integrator, time averager, output meter, and weighting networks, that is sensitive to pressure fluctuations. The instrument reads sound pressure levels when properly calculated with an acoustical calibrator accurate to 1 dB and is type I or type II as specified in ANSI S1.4-1971, or the latest approved revision thereof.
Use district.Those zoning districts established by the town’s zoning ordinance.
Vibration.A temporal and spatial oscillation or displacement, velocity, or acceleration in a solid material.
Vibration perception threshold.The minimum ground- or structure-borne vibrational motion necessary to cause a person to be aware of the vibration by such direct means as, but not limited to, sensation by touch or visual observation of moving objects.
(Ordinance 13-10 adopted 3/25/13; 2006 Code, sec. 8.302)