As used in this chapter:
ACCELERATION. The time rate of change of velocity.
AMBIENT NOISE. The all-encompassing noise associated with a given environment, being usually a composite of sounds from many sources.
ANSI. The American National Standards Institute or its successor bodies.
CONSTRUCTION NOISE. The noise emanating from construction activities as described in § 511.10.
CONTINUOUS SOUND. A sound with a duration greater than five minutes, characterized by an average sound pressure level that exceeds the fixed source noise levels described in § 511.12, measured as the root mean square (rms), and time-weighted average over any one hour period and requires for accurate measurement the instrumentation described in the definition for sound level meter hereof.
CRITICAL CONSTRUCTION EQUIPMENT. Construction equipment required to operate 24 hours a day to protect health and safety of the public and the workers.
CYCLE. The complete sequence of values of a periodic quantity that occur during a period and is referred to as cycles per second or hertz.
dbA. The A weighted sound pressure level obtained by the use of metering characteristics in the A weighting network specified in the latest edition of ANSI S1.4.
DECIBEL (db). A unit of measure, on a logarithmic scale to the base ten, of the ratio of the magnitude of a particular sound pressure, which for the purposes of this chapter shall be 20 micronewtons per square meter (MN/m2).
DISPLACEMENT. The magnitude of the motion.
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; work by private or public utilities when restoring utility services or protecting them from imminent danger.
FIXED SOURCE. A machine or device capable of creating a noise level at the property upon which it is regularly located, including, but not limited to: air conditioning and refrigeration apparatus, industrial and commercial process machinery, fan and the like.
IMPULSIVE SOUND. A sound occurring less frequently than once per second, characterized by a rapid rise in sound pressure such that it achieves its true peak pressure with a rise time of 35 milliseconds or less, and the peak sound pressure level exceeds the fixed source noise levels described in § 511.12, measured as the root mean square (rms), by ten dB, and which requires for accurate measurement the instrumentation described in the definition for sound level meter hereof.
INTERMITTENT SOUND. A sound with a duration greater than one second but less than five minutes, characterized by a rapid rise in sound pressure with a rise time of greater than 35 milliseconds, with an average sound pressure level that exceeds the fixed source noise levels described in § 511.12, measured as the root mean square (rms), by seven dBa, for the entire duration of the noise and requires for accurate measurement the instrumentation described in the definition for sound level meter hereof.
MOTOR VEHICLE. Includes, but is not limited to, automobiles, trucks, motorcycles, minibikes, go-carts and snowmobiles.
NOISE. Any undesired sound. NOISE LEVEL, for the purposes of this chapter, the terms NOISE LEVEL and SOUND LEVEL where used are synonymous.
PARTICLE VELOCITY. The time rate of change of displacement.
PERSON. Any person, person’s firm, association, co-partnership, joint venture, corporation or any entity public or private in nature.
SOUND. An oscillation in pressure in air.
SOUND LEVEL. In decibels, a weighted sound pressure level, measured by the use of metering characteristics and frequency weightings specified in ANSI Sd1.4 Specification for Sound Level Meters.
SOUND LEVEL METER. A properly calibrated instrument including a microphone, an amplifier, an output meter and frequency weighting networks for the measurement of noise and sound levels in a specified manner. The meter must satisfy the applicable requirements for an appropriate Type 1 or 2 SOUND LEVEL METER as defined in ASNI S1.4 - 1971 or the most recent revision.
SOUND PRESSURE LEVEL. In decibels, 20 times the logarithm to the base ten of the ratio of the magnitude of a particular sound pressure to a standard reference pressure, which for the purposes of this chapter shall be 20 micronewtons per square meter (i.e., 20u N/m2).
UNNECESSARY, EXCESSIVE OR OFFENSIVE NOISE. Any offensive sound or noise which annoys, disturbs, injures or endangers the comfort, repose, health, peace or safety of others; or a noise level which exceeds the fixed source noise level for the zone as provided in § 511.12, unless specified by a specific section, when measured at the property line of the noise source.
ZONING DISTRICTS. Those established by Title Five of the Planning and Zoning Code.
(Ord. 88-151, passed 12-11-1989)