§ 66-91. Definitions.

The following words, terms and phrases, when used in this division, shall have the meanings ascribed to them in this section, except where the context clearly indicates a different meaning:

Ambient noise means the all-encompassing noise associated with a given environment, being usually a composite of sound from many sources near and far.

A-weighted level (dBA) means the total broadband sound level of the noise spectrum as measured using the A-weighted network of a sound level meter. The unit of measurement is the dBA.

Continuous noise means a noise which remains essentially constant in level during the period of observation.

Decibel, dB means a division of a logarithmic scale used to express the ratio of two like quantities proportional to power or energy. The ratio is expressed in decibels by multiplying its common logarithm by 10.

Impulsive noise means a noise which is characterized by brief excursions of sound pressure which significantly exceed the ambient noise level.

Intermittent noise means a noise whose sound pressure level exceeds the ambient noise level at either regular or irregular intervals.

Noise level means the sound pressure level as measured in dBA unless otherwise specified. A measurement of noise must be at least five dB above the ambient noise level.

Sound level meter means an instrument to measure the sound pressure level of relatively continuous and broadband noises. The sound level meter used to determine compliance with this article shall meet or exceed the requirements for a type 2 sound level meter in accordance with ANSI standard S1.4.

Sound pressure level means the squared ratio, expressed in decibels, of the sound pressure under consideration to the standard reference pressure of 0.0002 dnye/cm . The ratio is squared because pressure squared, and not pressure, is proportional to energy.

(Code 1970, § 16¾-28; Ord. No. 74-10, § 3, 4-23-74)

Cross reference

Definitions generally, § 1-2.