§ 1 CONCISE SCIENTIFIC DEFINITIONS.

   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-Weighting Filter Network. This 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 micro pascal.

   FREQUENCY.  The number of periodic oscillations, vibrations or waves per unit time (usually one second).

   HERTZ (HZ). The unit used for measuring the frequency of a sound. The number of hertz is the number of cycles per second of a per 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 micro-pascal. The sound pressure level is expressed in decibels (DB).

SPL=20LOG10       (Sound Pressure A
            Sound Pressure B)

Sound Pressure A = Measured Sound Pressure

Sound Pressure B = Reference Sound Pressure (20 Micropascals)

(Ord. 2000-199, passed 12-20-2000)