An actuator is provided, including a plurality of conducting layers and a plurality of electret layers. The electret layers are respectively sandwiched between the conducting layers, and form gaps between the conducting layers. Directions of preset electric fields of the adjacent electret layers are opposite, and the adjacent conducting layers are respectively electrically connected to a first voltage end and a second voltage end to receive a driving voltage.

An actuator is provided, including a plurality of conducting layers and a plurality of electret layers. The electret layers are respectively sandwiched between the conducting layers, and form gaps between the conducting layers. Directions of preset electric fields of the adjacent electret layers are opposite, and the adjacent conducting layers are respectively electrically connected to a first voltage end and a second voltage end to receive a driving voltage.

A micro-electromechanical transducer including one or more moveable members, and a viscoelastic substance having a predetermined viscoelasticity, the viscoelastic substance being adapted to influence the response of the transducer in a predetermined manner. The micro-electromechanical transducer of the present invention may include a MEMS transducer, such as a MEMS microphone, a MEMS vibration sensor, a MEMS acceleration sensor, a MEMS receiver.

A micro-electromechanical transducer including one or more moveable members, and a viscoelastic substance having a predetermined viscoelasticity, the viscoelastic substance being adapted to influence the response of the transducer in a predetermined manner. The micro-electromechanical transducer of the present invention may include a MEMS transducer, such as a MEMS microphone, a MEMS vibration sensor, a MEMS acceleration sensor, a MEMS receiver.

Provided is a sheet-shape electrostatic sound pressure-electrical signal conversion device that is three-dimensionally deformable and has a low drive voltage.

The sound pressure-electrical signal conversion device includes a polymer sheet sandwiched between a pair of electrodes facing each other, the polymer sheet is a dielectric film, at least one of the electrodes includes an insulating flexible substrate having a plurality of through-holes and a plurality of conductive fibers having one end fixed to the flexible substrate with a pressure sensitive adhesive, electrical conduction in an in-plane direction is formed by contact between the conductive fibers, the conductive fibers are vibrated by giving an electrical signal to the pair of electrodes or the conductive fibers are vibrated by receiving sound pressure to cause the pair of electrodes to output an electrical signal.

In one embodiment of an audio system, a transducer can be coupled to a passive acoustic directional amplifier to provide various benefits and improvements, including improvements to: speech intelligibility, signal-to-noise ratio, effective equivalent input noise, at-a-distance acoustic signal reception, and directional preference. In another embodiment, the shape of an interior surface of a passive acoustic directional amplifier is provided. In another embodiment, the material properties of an interior surface of a passive acoustic directional amplifier are provided.

An electret microphone is provided, comprising a microphone capsule with an output connection, a first input connection as an earth connection and a second input connection for providing a supply voltage for the microphone capsule and for leading out a microphone output signal of the microphone capsule, and a cascode consisting of a first and second transistor. An output connection of the microphone capsule is provided as input of the cascode. The second transistor is configured as a field effect transistor FET and the gate connection thereof is coupled to the output connection of the microphone capsule. A drain connection of the second transistor is coupled to an emitter connection of the first transistor as bipolar transistor or to a source connection of the first transistor as an FET transistor. Furthermore, a third transistor is provided as bipolar transistor, whose emitter connection is coupled to the second input connection. A collector connection of the third transistor is coupled via a capacitor to earth. A base connection of the third transistor is coupled via a resistance to the second input connection. The base connection of the third transistor is coupled to a collector connection of the first transistor as bipolar transistor or to a drain connection of the first transistor as FET transistor. A resistance is coupled between the drain connection of the second transistor and the collector connection of the third transistor.

A micro-electro-mechanical system (MEMS) electrostatic speaker that comprises an array of cells, wherein each cell comprises an upper stator, a membrane, a lower stator and supporting elements configured to support the upper stator, the membrane and the lower stator; wherein a distance between the upper stator and the lower stator of each cell is of microscopic scale.

Magnetic field cancelling audio systems and associated devices are disclosed. In one embodiment, an audio system with two electromagnetic audio drivers positioned and electrically connected to reduce emitted magnetic fields over a range of predefined frequencies.

The present invention discloses a method for producing parametric sound using parametric sound system which is based on ultrasonic electrostatic transducers. It comprises modulation of a carrier ultrasonic signal with a processed audio signal in audio signal processor comprising adaptive frequency filtering based on the audio signal level, dynamic range compression, square root operation, amplification of the modulated ultrasonic signal using a D-class amplifier, driving an electrostatic transducer and generating modulated ultrasonic waves into the air. The electrostatic transducer for the parametric sound system comprises a specific back plate structure that improves electromechanical efficiency of the transducer and also enables realization of a phased array on a single back plate. The disclosed manufacturing method of the electrostatic transducer comprises producing sets of electrodes on the surface of the back plate forming individual cells.