Acoustics

Abstract

Acoustics is a very broad field of science that covers the generation, reduction, control, transmission, and reception aspects of sound. This chapter discusses three fundamental measures of sound. These are sound power, sound intensity, and sound pressure. In the field of acoustics, the decibel (dB), which is one‐tenth of a bel, is almost exclusively used. The first weighting filter to be discussed is called A weighting and usually carries the associated symbol dBA or dB(A). The chapter summarizes the fundamental theoretical developments of acoustics in a fluid. When a wave propagating in a medium encounters a change in the impedance presented to the wave, reflection and transmission of the wave occur. The chapter outlines some general concepts associated with the use of passive noise control for reducing unwanted noise and explains concepts associated with active noise control. Finally, hearing loss, community and environmental noise, and sound quality analysis, are presented.