Abstract: The invention relates to a transducer plate for electro-acoustic transducers, such as used in telecommunications technology, having a carrier plate and a ceramic plate arranged on a carrier plate. The invention teaches a transducer plate which is dimensioned so that it can be used in a microphone, a receiver or a piezoelectric VF ringing device despite the different voltage response factors required for each application. The following dimensions should preferably be used: transducer plate diameter (0.sub.2)=43 mm; ceramic plate diameter (0.sub.1)=30 mm; transducer plate thickness (d)=150 microns; and ceramic plate thickness (1)=90 microns.

Abstract: An electrical acoustical transducer is provided having a piezoelectrical layer in a housing with a transducer plate. The transducer plate divides the housing into a front chamber and a rear chamber. In the rear chamber, there is provided a Helmholtz resonator for the attenuation of resonance increases. With the invention a Helmholtz resonator is designed such that its acoustical characteristics do not change through environmental influences. Instead of covering the resonator by means of a customary silk disk, several narrow slots are arranged in the carrier plate.

Abstract: The invention concerns an electro-acoustical transducer with a transducer plate having a piezo electric layer and which subdivides the housing of the transducer into a front and back chamber. In the front chamber, means are provided for the attenuation of resonance increases comprising Helmholtz resonators and an attenuation disc. According to the invention, the Helmholtz resonators are designed in such a manner that their effective surface is not reduced in size by means of the attenuation disc or wafer. This is attained according to the invention in that slots are formed in a separating plate.

Abstract: A transducer plate for piezo-electrical transducers has a piezo-electrical layer or member applied thereon. Unwanted oscillations, in particular the fourth partial oscillation, are attenuated by providing a thickness of the adhesive layer chosen for attenuation properties, and which is thicker than prior art adhesive layers.

Abstract: An electroacoustic transducer in which resonance ratio effects above 3500 Hz are attenuated by acoustic means, wherein the transducer membrane is disposed in a cavity which is sub-divided thereby, the sound-receiving space at the front side of the membrane being sub-divided by a separation plate having acoustic transmission openings therein, a mounting cap forming the front wall of said sound-receiving space and provided with acoustic transmission openings therein, and an attenuation member disposed between the separation disk and the mounting cap, which forms a low-pass filter for sound traveling to said membrane. The invention has particular application in piezo microphones in telephone technology.

Abstract: A method and apparatus for processing piezoelectric bodies to have a permanent polarization for use as electroacoustic transducers or the like are described. During the application of a constant polarizing electric field to a piezoelectric body, the surfaces of the body, which for example, might be in the shape of a disc, have applied thereto a surface pressure. A clamping device having smooth surfaces is used for this purpose.

Abstract: An electroacoustic sound generator of the type having a diaphragm vibrating in the audio frequency range is described. The diaphragm is mounted in a housing which is constructed to form first and second volumes, the former being smaller than the latter. The housing has channels formed therein for communicating sonic energy to the exterior from the first interior volume portion. The first volume portion together with the channels form a Helmholtz resonator tuned to the frequency of the sonic energy to be radiated. The resonant frequency is determined by the product of the compliance of the first volume and the square of the ratio of the cross-sectional area of a channel to the surface area of the diaphragm.