No person shall make, continue or cause to be made or continued, any loud, unnecessary or unusual noise, or any noise which either annoys, disturbs, injures or endangers the comfort, repose, health, peace or safety of others within the limits of the City.
(Prior code § 5-17.1; Ord. 21-1722 § 2)
As used in this article:
"A band level"
means the total sound level of all noise as measured with a sound-level meter using the A weighting network. The unit is dbA.
"Day"
means the time period from 7:00 a.m. to 10:00 p.m.
"Decibel (db)"
means a unit of level which denotes the ratio between two quantities which are proportional to power; the number of decibels corresponding to the ratio to two amounts of power is 10 times the logarithm to the base 10 of this ratio.
"Emergency work"
means work made necessary to restore property to a safe condition following a public calamity, work required to protect persons or property from an imminent exposure to danger, or work by private or public utility service.
"Night"
means the time period from 10:00 p.m. to 7:00 a.m.
"Noise level in decibels"
means the A-weighted sound pressure level as measured using the slow dynamic characteristic for sound level meters specified in ASA S1 4-1961, American Standard Specification for General Purpose Sound Level Meters, or latest revision. The reference pressure is 20 micronewtons/square meter (2 x 10-4 microbar).
"Person"
means a person, firm, association, copartnership, joint venture, corporation or any entity, public or private in nature.
"Sound level meter"
means an 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 as specified in ASA S1 4-1961, American Standard Specification for General Purpose Sound Level Meters, or latest revision.
(Prior code § 5-17.2; Ord. 21-1722 § 2)
A. 
"Ambient noise" means the all-encompassing noise associated with a given environment being usually a composite of sounds with many sources near and far, without inclusion of intruding noises from isolated identifiable sources.
B. 
Unless sound-level meter readings determine the ambient noise level in a given environment to be higher, the ambient noise levels in Norwalk are presumed to be as follows:
Decibels
Time
Zone
45 dbA
Night
Residential
55 dbA
Day
Residential
60 dbA
Anytime
Commercial
65 dbA
Anytime
All other zones
(Prior code § 5-17.3; Ord. 21-1722 § 2)
A. 
Any decibel measurement made pursuant to provisions of article shall be based on a reference sound pressure of 0.0002 microbars as measured in any octave band with center frequency, in cycles per second, as follows: 63, 125, 250, 500,1000, 2000, 4000 and 8000 or as measured with a sound-level meter using the A weighting network, and using the slow meter response.
B. 
Measurements shall be taken with the microphone located at any point on the property line, but no closer than three feet from any wall and not less than three feet above the ground.
C. 
A minimum of three readings shall be taken at two minute intervals. The sound level shall be the average of these readings.
(Prior code § 5-17.4; Ord. 21-1722 § 2)
A. 
Use Restricted. Notwithstanding any other provision of this article and in addition to this article, it is unlawful for any person to wilfully make or continue, or cause to be made or continued, any loud, unnecessary or unusual noise which disturbs the peace or quiet of any neighborhood or which causes discomfort or annoyance to any reasonable person of normal sensitiveness residing in the area.
B. 
Prima Facie Violation. An average noise level reading measured pursuant to Section 9.04.130 which exceeds the ambient noise level at the property line of any residential land (or if a condominium or apartment house, within any adjoining apartment) by more than five decibels shall be deemed to be prima fade evidence of a violation of the provisions of this article.
(Prior code § 5-17.5; Ord. 21-1722 § 2)
In addition to the provisions of Section 9.04.140, the following specific acts are declared to be unlawful:
A. 
Radios, Television Sets and Similar Devices.
1. 
Use Restricted. It is unlawful for any person within the City to use or operate any radio receiving set, musical instrument, phonograph, television set, or other machine or device for the producing or reproducing of sound at any time in such a manner as to produce noise levels on residential land which would disturb the peace, quiet and comfort of neighboring residents or any reasonable person of normal sensitiveness residing in the area.
2. 
Prima Facie Violation. An average noise level reading measured pursuant to Section 9.04.130 which exceeds the ambient noise level at the property line of any residential land (or if a condominium or apartment) by more than five decibels shall be deemed to be prima facie evidence of a violation of the provisions of this article;
B. 
Horns, Signaling Devices, Etc. The sounding of any horn or signaling device on any vehicle on any street or public place except as a danger warning, or as required by law, or by safe driving practices; the creation by means of any such horn or signaling device of any unreasonably loud or prolonged or harsh sound; the use of any horn or signaling device operated by means other than by hand or electricity;
C. 
Loud Speaker and Amplifiers for Advertising. The using, operating or permitting to be played, used or operated of any machine or device for the producing or reproducing of sound which is broadcast upon the public streets for the purpose of commercial advertising or attracting the attention of the public to any building, structure or activity, except in compliance with the terms and conditions of a permit sought from and issued by the City;
D. 
Exhausts. The discharge into the open air of the exhaust of any steam engine, stationary internal combustion engine, motor boat or motor vehicle, except through a muffler or other device which effectively prevents loud or explosive noises;
E. 
Construction or Repairing of Buildings. The erection (including excavation), demolition, alteration, construction or repair of any building other than between the hours of 7:00 a.m. and 6:00 p.m. or sunset, whichever is later, except in the case of urgent necessity in the interest of public health and safety, and then only with a permit from the Building Official or Director of Community Development, which permit may be granted for a period not to exceed three days while the emergency condition continues, and which permit may be renewed for periods of three days or less while the emergency continues; if the Building Official or Director of Community Development should determine that public health, safety, comfort and convenience will not be impaired by the erection, demolition, alteration or repair of any building or the excavation of sites other than streets and highways within the hours of 6:00 p.m. or sunset, whichever is later, and 7:00 a.m., or any part, and that substantial loss or inconvenience would result to any party in interest denied permission to do so, he or she may grant permission for such work, or any part, to be done, within the hours of 6:00 p.m. or sunset, whichever is later, and 7:00 a.m., or any day, or at such times within such hours as he or she shall fix in accordance with such determination;
F. 
Hawkers and Peddlers. The shouting and crying, or the use of any sound-making device to attract attention, by peddlers, hawkers, itinerant merchants or itinerant vendors in any residential neighborhood, which disturbs the peace and quiet, or between the hours of 9:00 p.m. and 8:00 a.m.;
G. 
Pile Drivers, Hammers, Etc. The operation between the hours of 6:00 p.m. or sunset, whichever is later, and 7:00 a.m. of any pile driver, steam shovel, pneumatic hammer, derrick, hoist, or other appliances, the use of which is attended by loud or unusual noise, unless the Director of Building and Safety grants permission pursuant to the standards provided in subsection E of this section;
H. 
Engines and Motors. The operation of any electric motor or engine, the starting or running of which is attended by sudden, loud or unusual noise, unless such motor is enclosed within a sound-insulated structure so as to prevent such noise from being plainly audible at a distance of 50 feet from such structure, or within 10 feet of any residence;
I. 
Motor Vehicles. Racing the motor of any motor vehicle or needlessly bringing to a sudden start or stop any motor vehicle.
(Prior code § 5-17.6; amended during 1999 codification; Ord. 21-1722 § 2)
No permit shall be required to perform emergency work as defined in Section 9.04.110 nor shall the provisions of this article apply to those activities or undertakings of a public utility company and which relate to the normal maintenance and/or construction activities of the utility.
(Prior code § 5-17.7; Ord. 21-1722 § 2)