Abstract: A bender acoustic transducer has a flat, piezoelectric element affixed to a flat, elongated inert element. The ends of the inert element are hinged on a supporting rectangular frame which has a rectangular opening. Two sides of the elements are exposed so that when a voltage is applied, a dipole acoustic wave is generated by the transducer.

Abstract: An electroacoustic transducer having high acoustic-to-electric energy conversion per unit volume. The transducer is in the form of a body having a cylindrical central section and hemispherical end sections, the central section and the end sections formed from active piezoelectric material and electrically interconnected with respect to a pair of output terminals wherein the polarizations of the central section and the end sections are arranged to convert acoustic pressure on the entire external surface area of said body to be effective in producing electrical energy. The physical parameters of each section are matched to produce essentially equal electrical characteristics of each section to form an inherently symmetrical transducer. The transducer has high sensitivity for a small size and is especially adapted for use in thin line towed arrays. The symmetrical form, polarities and balanced connections of the transducer provide cancellation of forces due to acceleration.

Abstract: An alarm buzzer for fire alarms, burglar alarms, and the like, is provided using a conventional piezoelectric transducer driven by a battery operated oscillator and mounted in a casing. The casing has a resonance cavity formed therein with the transducer mounted adjacent thereto and having an open end. A grill is mounted to the casing and extends over the resonant cavity and spaced therefrom by a predetermined spacing and a reflector plate is mounted onto the grill covering the grill portion facing the resonant cavity, whereby the efficiency of an alarm buzzer is increased by the combination of a resonance cavity and folded horn.

Abstract: An acoustic transducer for simultaneously producing broadband sound sources n the conventional and overtone resonance modes. Two sets of ceramic and aluminum discs are fixed adjacent each other with the ceramic discs of each set facing one another across an air gap. By selection of respective relative diameters and thicknesses for the ceramic and aluminum discs, the transducer exhibits dual resonance output signals when excited by an input voltage.

Abstract: An electromagnetic, high compliance, high displacement low frequency underwater sound transducer is provided for use at great depths without gas compensation. Fluid filled chambers having flexible walls of predetermined area and compliance provide proper acoustic impedance to allow large transducer diaphragm displacements to radiate high power with reasonable efficiency when connected to a chamber located behind the transducer diaphragm.