The measurement of sound and light is important as it relates to the sense of hearing and sight, as well as many industrial applications, such as the use of sound waves for the detection of flaws in solids and in location and linear distance measurement. Sound pressure waves can induce mechanical vibration and hence failure. Excessive sound levels produce noise pollution. Light and its measurement is used in many industrial applications for high-accuracy linear measurements, location of overheating (e.g., infrared), object location and position measurements, photo processing, scanning, readers (e.g., bar codes), and so forth.