The present invention discloses a speaker, which includes a basket, a vibration system fixed to the basket, and a magnetic circuit system arranged in the basket. The vibration system includes a first diaphragm fixed to the basket and a second diaphragm oppositely separated from the first diaphragm, the magnetic circuit system includes an upper clamping plate fixed to the basket, and the upper clamping plate is disposed separately from the second diaphragm. The upper clamping plate includes a fixing portion fixed to the basket, the upper clamping plate is provided with a step recessed towards the first diaphragm from one side of the upper clamping plate facing away from the first diaphragm, and the step is connected with the fixing portion.

Provided are an acoustic diaphragm and an acoustic device including the same. The acoustic diaphragm may include graphene nanoparticles, and an average particle size of the graphene nanoparticles may be about 10 nm or less. The graphene nanoparticles substantially may have a particle size of about 1 nm to about 10 nm. The graphene nanoparticles may include at least one functional group selected from a hydroxyl group, a carboxyl group, a carbonyl group, an epoxy group, an amine group, and an amide group.

Provided are an acoustic diaphragm and an acoustic device including the same. The acoustic diaphragm may include graphene nanoparticles, and an average particle size of the graphene nanoparticles may be about 10 nm or less. The graphene nanoparticles substantially may have a particle size of about 1 nm to about 10 nm. The graphene nanoparticles may include at least one functional group selected from a hydroxyl group, a carboxyl group, a carbonyl group, an epoxy group, an amine group, and an amide group.

An ultrasonic measurement apparatus has an ultrasonic transducer device including an ultrasonic element array, a first through n-th first end-side terminal XA1 to XAn provided to a first end side, and a first through n-th second end-side terminal XB1 to XBn provided to a second end side opposing the first end side; a first transmission circuit outputting first drive signals VTA1 to VTAn to the first through n-th first end-side terminals XA1 to XAn; and a second transmission circuit outputting second drive signals VTB1 to VTBn to the first through n-th second end-side terminals XB1 to XBn.

A MEMS transducer for interacting with a volume flow of a fluid includes a substrate which includes a layer stack having a plurality of layers which form a plurality of substrate planes, and which includes a cavity within the layer stack. The MEMS transducer includes an electromechanical transducer connected to the substrate within the cavity and including an element which is deformable within at least one plane of movement of the plurality of substrate planes, deformation of the deformable element within the plane of movement and the volume flow of the fluid being causally correlated. The MEMS transducer includes an electronic circuit arranged within a layer of the layer stack, the electronic circuit being connected to the electromechanical transducer and being configured to provide a conversion between a deformation of the deformable element and an electric signal.

According to one embodiment, a sensor includes a structure body including a deforming portion, and a first sensing element provided at the deforming portion. The first sensing element includes first to fourth magnetic layers and a first intermediate layer. The first magnetic layer is provided between the second and third magnetic layers. The fourth magnetic layer is provided between the first and third magnetic layers. The first intermediate layer is provided between the second and first magnetic layers. The third magnetic layer includes at least one of a first material or a second material. The first material includes at least one selected from the group consisting of IrMn, PtMn, PdPtMn, and RuRhMn. The second material includes at least one of CoPt, (Co.sub.xPt.sub.100-x).sub.100-yCr.sub.y, or FePt. A crystallinity of at least a portion of the fourth magnetic layer is higher than a crystallinity of the first magnetic layer.

A sound producing device includes an air pulse generating element and a control unit. The air pulse generating element includes an air chamber, a membrane, a first air entrance and a first valve. The membrane is disposed in the air chamber. The first air entrance is disposed at a side of the membrane in a first direction. The first valve is disposed between the first air entrance and the membrane. The control unit generates a driving signal to control a movement of the membrane, such that the air pulse generating element generates an air pulse in response to the driving signal. During an operation, an first airflow corresponding to the air pulse flows into or flows out of the air chamber through the first air entrance, and passes through the first air entrance substantially along a direction parallel to the first direction perpendicular to the moving direction of the membrane.

A sound producing device includes an air pulse generating element and a control unit. The air pulse generating element includes an air chamber, a membrane, a first air entrance and a first valve. The membrane is disposed in the air chamber. The first air entrance is disposed at a side of the membrane in a first direction. The first valve is disposed between the first air entrance and the membrane. The control unit generates a driving signal to control a movement of the membrane, such that the air pulse generating element generates an air pulse in response to the driving signal. During an operation, an first airflow corresponding to the air pulse flows into or flows out of the air chamber through the first air entrance, and passes through the first air entrance substantially along a direction parallel to the first direction perpendicular to the moving direction of the membrane.

A bone conduction device includes split high-frequency and low-frequency actuators. The frequency response of the low-frequency actuator can be restricted to the lower range of hearing frequencies to improve performance. The high-frequency actuator can be implanted under tissue close to the cochlea to improve transmission efficiency, since high-frequency vibrations suffer greater attenuation.

According to one embodiment, a sensor includes a supporter, a film portion, a first element, and a first magnetic portion. The supporter includes a first support portion and a second support portion. The film portion includes a first partial region supported by the first support portion. The first element is provided at the first partial region. The first element includes a first electrode region, a first opposing electrode region, and a first magnetic layer provided between the first electrode region and the first opposing electrode region. A direction from the second support portion toward the first magnetic portion is aligned with a first direction. The first direction is from the first opposing electrode region toward the first electrode region. At least a portion of the first magnetic portion overlaps at least a portion of the first element in a direction crossing the first direction.