Kim Yang-Hann, Choi Jung-Woo. Sound visualization and manipulation

John Wiley & Sons Singapore Pte. Ltd, 2013. — 438 p. ISBN: 978-1-118-36847-3Visual representation of acoustic phenomena. Solid mathematical apparatus.From the prefaceIf only we could see sound propagation in space with our eyes, and if only the sound could be created in any desired shape! Such a fantastic concept is being realized. New approaches to acoustics and noise engineering have allowed innovative changes in these fields.So far, extensive efforts have been made using various methods to explain how a medium changes as sound propagates in space or how the shape of the sound propagation changes depending on its frequency and wavelength. There are two main approaches being employed to resolve these questions: theoretical and experimental. The theoretical approach is adopted to develop an understanding of the phenomena of sound propagation in acoustic waves and, through this understanding, to attempt to find a solution. The characteristics of acoustic wave equations in certain cases are interpreted by numerically solving the so-called linear acoustic wave equations. Popular numerical techniques are the finite element method and boundary element method; both have achieved incredible developments owing to continuous evolutions in their background theories and improvements in the arithmetic capacity of computers. The experimental approach has also seen rapid improve-ments. Developments in semiconductor technologies have reduced the microphone size to eliminate unnecessary scattering induced by them, and the reduction in cost allows for tens and hundreds of microphones to be used at the same time. We can now sample, record, and analyze signals from hundreds of microphones in almost real time. These developments allow us to visualize sound using our eyes in the real world, which is something that human beings have long dreamt of.