§ 91.15 DEFINITIONS.
   For the purpose of this subchapter, the following definitions apply unless the context clearly indicates or requires a different meaning. All terminology used in this subchapter shall be in conformance with applicable publications of the American National Standards Institute (ANSI) or its successor body.
   A-WEIGHTED SOUND LEVEL. The loudness of a sound measured through a filtering device intended to simulate human hearing. The level is designated dB(A) or dBA. The sound pressure level of a sound measured through an A-weighting filter network. The level read is designated dB(A) or dBA.
   COMMERCIAL ZONE. Zones B-1 and B-2 as established in the zoning ordinance of the city.
   DECIBEL (dB). A unit for measuring the sound pressure level of a sound. The unit used for comparing the sound pressure level of a sound to the sound pressure level of a reference sound having a sound pressure of 20 micropascals.
   FREQUENCY. An objective way to describe the pitch of sound. The number of periodic oscillations, vibrations, or waves per unit time (usually one second).
   HERTZ (Hz). A unit for measuring the frequency of a sound (sometimes called CYCLES PER SECOND). The unit used for measuring the frequency of a sound. The number of HERTZ is the number of cycles per second of a periodic sound pressure wave.
   INDUSTRIAL ZONE. Zone I-1 as established in the zoning ordinance of the city.
   LIGHT MOTOR VEHICLE. Any motorized vehicle with gross vehicular weight less than 8,000 lbs., including automobiles, vans, motorcycles, motor-driven cycles, motor scooters, dune buggies, snowmobiles, all-terrain vehicles, go-karts, minibikes, trail bikes, and light trucks.
   MODIFIED EXHAUST SYSTEM. Any exhaust system in which the original noise abatement devices have been removed, altered, or replaced to produce more noise.
   NOISE. Any unwanted sound.
   OCTAVE BAND. A way to divide the entire frequency range of sound into sections for more accurate measurements. A portion of the entire sound frequency spectrum contained between two frequencies A and B such that A=2b.
   PERSON. Any individual, firm, partnership, association, corporation, company, or organization of any kind.
   PLAINLY AUDIBLE. Any noise for which the information content is unambiguously communicated to the listener, including understandable spoken speech, comprehension, or whether a voice is raised (agitated) or normal or comprehensible musical rhythms.
   RESIDENTIAL ZONES. Zones R-1, R-2, and R-3 as established in the zoning ordinance of the city.
   SOUND LEVEL METER. An instrument designed to measure sound pressure levels.
   SOUND PRESSURE LEVEL. An objective way to describe the loudness of a sound. Means 20 times the logarithm (base ten) of the ratio of the measured sound pressure to a reference pressure of 20 micropascals. The SOUND PRESSURE LEVEL is expressed in decibels (dB).
(Ord. 9, 1993, passed 5-18-1993)