and/or quantify sound emissions from a variety of industrial sources. This article provides an overview of basic acoustical fundamentals, including the frequency ranges of primary interest, how to deal with decibels, and the different types of sound level metrics. Important acoustical testing parameters, criteria, and appropriate exclusions and corrections are also reviewed.
Most sound waves consist of a number of superimposed sounds at different frequencies. The frequency of a sound
wave is perceived as pitch (high or low). The unit of frequency is the Hertz (Hz), also referred to as cycles per second
(cps). The average healthy person hears sounds ranging from a frequency of 20 Hz to 20,000 Hz (20 kHz).1