Acoustical Engineering - Fundamental Science

Fundamental Science

Although the way in which sound interacts with its surroundings is often complex, there are a few ideal sound wave behaviors that are fundamental to understanding acoustical design. Basic sound wave behaviors include absorption, reverberation, diffraction, and refraction. Absorption is the loss of energy that occurs when a sound wave reflects off of a surface. Just as light waves reflect off of surfaces, sound waves also reflect off of surfaces, and every reflection results in a loss of energy. Absorption refers both to the sound that transmits through and the energy that is dissipated by a material. Reverberation is the persistence of sound that is caused by repeated boundary reflections after the source of the sound stops. This principle is particularly important in enclosed spaces. In addition to reflecting off of surfaces, sound waves also bend around surfaces in the path of the waves. This bending is known as diffraction. Refraction is another kind of sound wave bending. This type of bending, however, is caused by changes in the medium through which the wave is passing and not the presence of obstacles in the path of a sound wave. Temperature gradients, for example, cause bending in sound waves. Acoustical engineers apply these fundamental concepts, along with complex mathematical analysis, to control sound for a variety of applications.