Ceramic Disc

Sound is the best known energy for underwater application. Hydrophone are receiving transducers designed to convert the acoustic pressure into electrical signal. Hydrophone are often capable of working over a wide frequency band.
A hydrophone is used in underwater for recording or listening underwater sound. The use of underwater sound is recent technology development and it is now part of the most human activities at sea. Its technology is applied in the oceans, scientifically, military or industrially. The number and type of application has grown considerably and primarily they are used in underwater to detect and locate obstacles and targets. They are also used to measure either the characteristics of the marine environment (Seafloor topography, living organisms, currents and hydrological structure etc.) or the location and velocity of an object moving underwater.