The Science and Applications of Acoustics

The science of acoustics deals with the creation of sound, sound transmission through solids, and the effects of sound on both inert and living materials. As a mechanicaleffect,soundisessentiallythepassageofpressure?uctuationsthrough matter as the result of vibrational forces acting on that medium. Sound possesses the attributes of wave phenomena, as do light and radio signals. But unlike its electromagnetic counterparts, sound cannot travel through a vacuum. In Sylva Sylvarumwrittenintheearlyseventeenthcentury,SirFrancisBacondeemedsound tobe“oneofthesubtlestpiecesofnature,”buthecomplained,“thenatureofsound in general hath been super?cially observed. ” His accusation of super?ciality from the perspective of the modern viewpoint was justi?ed for his time, not only for acoustics, but also for nearly all branches of physical science. Frederick V. Hunt (1905–1967), one of America’s greatest acoustical pioneers, pointed out that “the seeds of analytical self-consciousness were already there, however, and Bacon’s libelagainstacousticswaseventuallydischargedthroughthe?oweringofaclearer comprehension of the physical nature of sound. ” Modern acoustics is vastly different from the ?eld that existed in Bacon’s time and even 20 years ago. It has grown to encompass the realm of ultrasonics and infrasonics in addition to the audio range, as the result of applications in mate- als science, medicine, dentistry, oceanology, marine navigation, communications, petroleum and mineral prospecting, industrial processes, music and voice synt- sis,animalbioacoustics,andnoisecancellation. Improvementsarestillbeingmade in the older domains of music and voice reproduction, audiometry, psychoaco- tics, speech analysis, and environmental noise control.