Provided is a laminated piezoelectric element is formed by folding back and laminating a piezoelectric film having an electrode layer and a protective layer on both sides of a piezoelectric layer in which piezoelectric particles are dispersed in a matrix. In the laminated two layers of the piezoelectric film, in a case where a thickness of a central portion thereof is a center thickness and a position up to twice the center thickness in a direction from the folded side end part toward the center is the folded-back portion, there is a position at which the thickness is greater than the center thickness in the folded-back portion, and there is an air gap in the folded-back portion or the air gap is filled with a cementing agent. The laminated piezoelectric element is able to prevent peeling of the electrode layer and the like in the folded-back portion in the laminated piezoelectric element in which the piezoelectric film is folded back and laminated. An electroacoustic transducer uses the laminated piezoelectric element.

A MEMS sound transducer includes a substrate, a membrane formed within the substrate, and a bending actuator applied onto the membrane. The membrane includes at least one integrated permanent magnet and is electrodynamically controllable. The bending actuator can be piezoelectrically controlled separately from the membrane.

A display device includes: a display panel including a substrate and a pixel array layer disposed on a surface of the substrate; a sound generation device disposed on an opposing surface opposite to the surface of the substrate; and a set cover including a plurality of ribs which overlap the sound generation device in a thickness direction of the display panel. The sound generation device vibrates the display panel to output a sound.

A medical device prosthesis, including a housing and a piezoelectric transducer including a piezoelectric component, wherein the piezoelectric transducer is supported in the housing via at least one spring. In some embodiments, the medical device prosthesis is a bone conduction device, such as a transcutaneous passive or active bone conduction device.

Provided are an electroacoustic transduction film in which conversion between a vibration and a voltage is able to be appropriately performed without the occurrence of dielectric breakdown of the air between upper and lower thin film electrodes even when a high voltage is applied therebetween, a user is able to be prevented from coming into contact with a piezoelectric layer, and high productivity is achieved, and a manufacturing method of an electroacoustic transduction film. A piezoelectric layer which stretches and contracts in response to a state of an electric field, an upper thin film electrode formed on one principal surface of the piezoelectric layer, a lower thin film electrode formed on the other principal surface of the piezoelectric layer, an upper protective layer formed on the upper thin film electrode, and a lower protective layer formed on the lower thin film electrode are included, and a groove which penetrates the thin film electrode and the protective layer is formed in at least a portion of an outer peripheral portion in a surface direction of at least one of the upper thin film electrode and the upper protective layer, or the lower thin film electrode and the lower protective layer.

A medical device prosthesis, including a housing and a piezoelectric transducer including a piezoelectric component, wherein the piezoelectric transducer is supported in the housing via at least one spring. In some embodiments, the medical device prosthesis is a bone conduction device, such as a transcutaneous passive or active bone conduction device.

An electro-acoustic transducer includes a base and a plurality of vibration portions. Each of the vibration portions includes a piezoelectric transduction layer and has two connection ends and a free end. The connection portions are connected to the base, and the free ends are separated from one another. The piezoelectric transduction layers are adapted to receive electrical signals to deform, such that the vibration portions are driven to vibrate and generate corresponding acoustic waves. The vibration portions are adapted to receive acoustic waves to vibrate, such that the piezoelectric transduction layers are driven to deform and generate corresponding electrical signals.

A condenser microphone comprises a substrate, a vibratile diaphragm and a back plate. The substrate has an opening. The diaphragm is disposed corresponding to the substrate and covers the opening, and has a plurality of protrusions. The back plate is coupled to the diaphragm and has a plurality of through holes, at least some of which are corresponding to the protrusions respectively. An interval is formed between the diaphragm and the back plate, and when the diaphragm vibrates, the protrusions move into or further near the through holes.

Embodiments are disclosed for a loudspeaker driven by one or more piezoelectric actuators. In embodiments of the disclosure, a loudspeaker comprises a support structure, and a piezoelectric layered cantilever actuator affixed to the support structure via at least two grips. The support structure may also comprise a membrane suspended over the piezoelectric actuator, the membrane being in contact with the piezoelectric actuator between the at least two grips.

An audio system comprises an array of transparent piezoelectric transducers on a transparent surface. Each transparent piezoelectric transducer includes one or more piezoelectric layers and one or more conductive layers that are substantially transparent to visible light. A transparent piezoelectric transducer may include, e.g., a first conductive layer, a first piezoelectric layer on the first conductive layer, and a second conductive layer on the first piezoelectric layer. Or in another example, the transparent piezoelectric transducer includes many (e.g., 20-30) piezoelectric layers and many (e.g., 20-30) conductive layers.