The concise, scientific definitions of the terms used in this chapter shall be:
A-WEIGHTED SOUND LEVEL. The sound pressure level of a sound measured through an a- weighted filter network. The level read is designated dB(A) or dBA.
DECIBEL (dB). 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. The number of periodic oscillations, vibrations, or waves per unit time (usually one second).
HERTZ. The unit for measuring the frequency of a sound. The number of hertz is the number of cycles per second of a periodic sound pressure wave.
OCTAVE BAND. A portion of the entire sound frequency spectrum contained between two frequencies A and B such that A = 2B.
SOUND PRESSURE LEVEL. Twenty times the logarithm (base 10) of the ratio of the measured sound pressure to a reference pressure of 20 micropascals. The sound pressure level is expressed in decibels (dB).
Sound Pressure A
SPL = 20LOG10 10
Sound Pressure B
Sound Presure A = Measure Sound Pressure
Sound Pressure B = Referenced Sound Pressure
(10 Micropascals)
(Prior Code, Ch. 94, App. A) (Ord. 1116A, passed 4-13-1993)