As used in this chapter, specific words and phrases are defined as follows:
"A-weighted sound level"shall mean the sound pressure level in decibels as measured on a sound level meter using the A-weighted filter network. The A-weighting filter de-emphasizes the very low and very high frequency components of the sound in a manner similar to the response of the human ear. A numerical method of rating human judgment of loudness.
"Ambient noise level"shall mean the composite of noise from all sources, near and far. In this context, the ambient noise level constitutes the normal or existing level of environmental noise at a given location.
"Community noise equivalent level (CNEL)"shall mean the average equivalent A-weighted sound level during a twenty-four (24) hour day, obtained after the addition of five decibels to sound levels in the evening from seven to ten p.m. and after the addition of ten (10) decibels to sound levels in the night between ten p.m. and seven a.m.
"Decibel (dBA)"shall mean a unit for measuring the amplitude of a sound, equal to twenty (20) times the logarithm to the base ten (10) of the ratio of pressure of the sound measured to the reference pressure of twenty (20) micro-pascals.
"Equivalent sound or noise level (Leq)"shall mean the sound level corresponding to a steady noise level over a given sample period with the same amount of acoustic energy as the actual time-varying noise level. The energy average noise level during the sample period.
"Habitable room"shall mean any room meeting the requirements of the California Building Code or other applicable regulations which is intended to be used for sleeping, living, cooking, or dining purposes, excluding such enclosed spaces as closets, pantries, bath or toilet rooms, service rooms, connecting corridors, laundries, unfinished attics, foyers, storage spaces, cellars, utility rooms, and similar spaces.
"Impulsive noise"shall mean a noise of short duration usually less than one second and of high intensity, with an abrupt onset and rapid decay. Such objectionable noises may also be repetitive.
"Intrusive noise"shall mean that noise that intrudes over and above the ambient noise at a given location. The relative intrusiveness of a sound depends upon its amplitude, duration, frequency, time of occurrence and tonal information content, as well as the prevailing ambient noise level.
"L(n)"shall mean the A-weighted sound level exceeded during a certain percentage of the sample time. For example, L10 in the sound level exceeded ten percent (10%) of the sample time. Similarly, L50, L90, L99, etc.
"Noise"shall mean any unwanted sound or sound that is undesirable because it interferes with speech and hearing, is intense enough to damage hearing, or is otherwise annoying.
"Outdoor living area"shall mean outdoor spaces that are associated with residential land uses typically used for passive recreational activities or other noise-sensitive uses. Such spaces include patio areas, barbecue areas, jacuzzi areas, etc., associated with residential uses; outdoor patient recovery or resting areas associated with hospitals, convalescent hospitals, or rest homes; outdoor areas associated with places of worship which have a significant role in services or other noise-sensitive activities; and outdoor school facilities routinely used for educational purposes which may be adversely impacted by noise. Outdoor areas usually not included in this definition are: front yard areas, driveways, greenbelts, maintenance areas and storage areas associated with residential land uses; exterior areas at hospitals that are not used for patient activities; outdoor areas associated with places of worship and principally used for short-term social gatherings; and outdoor areas associated with school facilities that are not typically associated with educational uses prone to adverse noise impacts (for example, school play yard areas).
"Sound level (noise level)"shall mean the weighted sound pressure level obtained by use of a sound level meter having a standard frequency filter for attenuating part of the sound spectrum.
"Sound level meter"shall mean an instrument, including a microphone, an amplifier, an output meter, and frequency weighting networks for the measurement and determination of noise and sound levels.
(Ord. 07-17 § 2 (part); Ord. 22-13 § 3 (Exh. A))