Ultrasound refers to sound waves with frequencies exceeding 20 kiloHertz (kHz) of the sonic spectrum, which is the upper limit audible to humans.
The ultrasonic transducer is the electronic device used to create these sound waves, by means of converting electrical energy into sound energy (pressure).
Pressure fields created by the ultrasounds can be applied to a solid, liquid or gas medium, to alternately compress and stretch the molecular structure of the medium. Nowadays, ultrasound is used in many different sectors and applications: to, such as for the detection of objects and measurement of distances in medical imaging, or in industry for cleaning, mixing, and accelerating chemical processes, among other applications.