1 To comply with Department of Defense changes to common access cards, and to comply with Homeland Security Presidential Directive 12, the Fort Knox One Stop In-processing Center has recently started implementing changes to the CAC issuing process.
acoustics - the study of the physical properties of sound. acoustic radiation pressure - (acoustics) the pressure exerted on a surface normal to the direction of propagation of a sound wave. physical science, physics - the physical properties, phenomena, and laws of something; he studied the physics of radiation. harmonics - the study of musical sound.
The study of acoustics involves sound, ultrasound, infrasound and vibration waves in all 3 physical states of matter: solids, liquids and gases. Acoustical engineers or acousticians are the titles provided to physicists who specialize in this branch of science.