Tonpilz

The term tonpilz generally refers to a certain type of underwater electro-acoustic transducer. By sandwiching active (i.e. piezoelectric or magnetostrictive) materials between a light, stiff radiating head mass and a heavy tail mass, the transducer can effectively operate as either a projector (source) or a hydrophone (underwater acoustic receiver). The transducer's size, odd shape, and acoustic projection capabilities have earned it the moniker "tonpilz," which in German literally means, "singing mushroom." [O.B. Wilson, "Introduction to Theory and Design of Sonar Transducers", Peninsula Publishing, 1988]

Typically, tonpilz transducers are used in sonar applications. To maximize efficiency transducers are often placed in arrays—a grid of sometimes hundreds of transducers. This arrangement also allows for beam forming and steering.

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