Acoustics, Vibrations, and Integrated Building Systems

Abstract

Sound is transmitted by waves. These waves travel through gases, liquids, and solids alike. Wave action is mainly a transfer of energy. In the case of sound, this transfer takes the form of tiny motions at the molecular level. In gases and liquids, a sound wave shifts molecules slightly in a direction parallel to itself, that is, in a lengthwise direction. In solids, motion may also occur perpendicular to the wave. Sound waves spread from their source in all directions. The speed of sound is independent of loudness of tone. The sounds from a radio in a room, whether they are loud or soft, of high pitch or low, all reach a listener simultaneously.