The Science of Soundwaves and Their Applications
The Science of Soundwaves and Their Applications
The science of the sound wave is important in everyday life, from its use in car mufflers to the high tech office. In this paper I’m going to talk about the sound wave and describe its characteristics, show how this science was applied to muffler design, and computer design.
Sound is a pressure wave that consists of tiny fluctuations in the air pressure. The amplitude in general, is the maximum change in value of a parameter during the oscillation of a wave. In amplitude, that parameter will usually be pressure. The amplitude of a sound is the loudness of the sound. In illustration, this is the distance between a peak or trough. See illustration on previous page.
The frequency is defined as the number of vibrations, oscillations, or cycles in a repeating process occurring per unit time. In the context of sound, it is the number of compressions passing a fixed point of reference in one second. The resulting unit of frequency is called Hertz (Hz). Frequency is perceived as pitch.
Intensity is the rate at which sound energy flows through a defined area. Since the flow of energy is power, the dimensions of sound intensity are power/area. Usually, sound intensity is measured in watts/meter2. Intensity is perceived as loudness.
Interference is a synonym for superposition. Constructive interference is the amplitude of the combined wave, which is created by superposition and is greater than the amplitude of either component wave. Destructive interference is the amplitude of the combined wave created by superposition and is less than the amplitude of either component wave.
Superposition is a concept that describes the way in which sound waves, and waves more generally, interact. In essence, two waves passing through the same point in space at the same time combine in a linear fashion to create a single new wave. If the displacement from equilibrium caused by the first wave equals "a" and the displacement from equilibrium caused by the second wave equals "b", the resulting displacement from equilibrium for the combined wave will be "a + b". This is an algebraic addition. Since "a" and "b" can be positive, negative, or equal to zero, the resulting sum can also be positive, negative, or equal to...