1994 Ordinances - Laserfiche WebLink

Home Browse Search

(2) Ambient noise. The all-encompassin9 noise associated with a given environment, being usually a composite of sounds from many sources near and far. Ambient noise levels are established by taking a series of observations on the adversely affected property. It is the sound level that is exceeded 90% of the time in this set of observations. (3) Commercial area. As defined in the City of Portsmouth's zoning ordinance (hereinafter identified as "zoning ordinance"). (4) Construction area. Any site preparation, assembly, erection, substantial repair, alteration or similar action for or of public or private rights-of-way, structures, utilities or similar property. (5) Decibel (dB). A unit for measuring the volume of sound, equal to twenty (20) times the logarithm to the base 10 of the ratio of the pressure of the sound measured to the reference pressure, which is twenty (20) micropascals (twenty (20) micronewtons per square meter). (6) Discrete tone. A noise measured on a one-third octave band analyzer which is ten (10) decibels greater than each of the adjacent one-third octave bands. (7) Emergency means. Any occurrence or set of circumstances involving actual or imminent physical trauma or property damage which demands immediate action. (8) Impulsive noise. A noise, containing excursions usually of no more than one second, the A-weighted sound pressure level of which exceeds the ambient noise level by more than twenty decibels (20 dB(A)), when measured by the fast meter characteristic of a sound level meter. (9) Impulsive sound. Sound of short duration usually less than one second, with an abrupt onset and rapid decay. (10) Industrial area. As defined by the zoning ordinance. (11) Muffler or sound dissipating device. A device for abating the sound of escaping gases of an international combustion engine. (12) Noise. Any sound which annoys or disturbs humans or which causes or tends to cause an adverse psychological or physiological effect on humans.