Ultrasound is used for diagnostic scanning, ultrasound therapy and the ablation or destruction of unwanted tissues.
There are also a number of industrial applications of ultrasound technology – most notably sonochemistry, emulsification, welding, cleaning and non-destructive testing.
Diagnostic ultrasound, used widely in managing pregnancy, is the application that most people are familiar with.
Infrasound is created by various natural sources, such as earthquakes, thunderstorms, wind and waves. Comparable oscillary changes in air pressure may be experienced when running. Artificial sources of infrasound include explosions, compressors, low speed fans, wind turbines, trains and building sway.