Fundamentals of Acoustics

Chapter 2 covers the fundamental concepts of acoustical engineering including sound waves, frequency and wavelength, simple harmonic motion, superposition of waves, phase relationships, sound velocity, sound levels, and the characterization of sound sources. The fundamental equations concerning these concepts are presented in the chapter along with a more detailed discussion of propagation of sound in free space. This latter discussion includes details of the spherical spreading of sound from point sources including factors such as directionality, directivity, and directivity index. The chapter ends by modeling line sources (one-dimensional sounds sources) and planar sources (two-dimensional, large, flat surfaces).