Abstract: A sound transducer, which may be a microphone or a speaker, is constructed using a metallic film sandwich of piezoelectric film as the active element. The sandwich is laminated to a flat inflexible substrate, such as a printed circuit board, over substantially its entire surface area, so that it operates as a transducer without flexing the piezoelectric film. Since the piezoelectric film is less sensitive in this mode than when it flexes, either the area of the sandwich must be large, or, as a microphone, the transducer must be subject to powerful sound waves. Such powerful sound waves are most easily achieved by either putting the microphone in physical contact with the sound source or placing the microphone in a contained pressure-field with the sound source. This entire package is then provided with impedance matching to connect it to an external point where the resulting signal can be used, is provided with a ground shield, and is encased in waterproof layers.