Embodiments are disclosed of a speaker capable of producing multi-frequency-range sound using bar magnets, multiple diaphragms, and a shared planar voice coil. The planar voice coil is located between the bar magnets and translates a received electric signal into the kinetic energy that vibrates the diaphragms, thus reproducing multi-frequency range sound. In some embodiments, the speaker generates bi-directional sound.

A vibration generating device includes a housing; a diaphragm supported by the housing, and configured to generate sound by vibrating in a first direction; and a vibration providing part attached to the housing, and configured to vibrate the housing. The vibration providing part vibrates the housing in the first direction at a first frequency, and vibrates the housing in a second direction at a second frequency lower than the first frequency.

A micro-electro-mechanical system (MEMS) microphone is provided. The MEMS microphone includes a substrate, a backplate disposed on a side of the substrate, and a diaphragm movably disposed between the substrate and the backplate. The diaphragm includes a plurality of implantation portions, and the implantation portions have different concentration-depth profiles.

A micro-electro-mechanical system (MEMS) microphone is provided. The MEMS microphone includes a substrate, a backplate disposed on a side of the substrate, and a diaphragm movably disposed between the substrate and the backplate. The diaphragm includes a plurality of implantation portions, and the implantation portions have different concentration-depth profiles.

An acoustic device and method generates an acoustic signal by applying an excitation signal to a first coil disposed about an armature of an acoustic receiver. A second coil magnetically coupled to the first coil generates an electrical output signal in response to the excitation signal applied to the first coil, wherein the output signal of the second coil is indicative of a change in a state or operation of the receiver or acoustic device. In some embodiments, the first and second coils are wired independently of each other, and the acoustic device further includes an electrical circuit which determines the change in the acoustic performance based on a change in the electrical output signal of the second coil.

An acoustic device and method generates an acoustic signal by applying an excitation signal to a first coil disposed about an armature of an acoustic receiver. A second coil magnetically coupled to the first coil generates an electrical output signal in response to the excitation signal applied to the first coil, wherein the output signal of the second coil is indicative of a change in a state or operation of the receiver or acoustic device. In some embodiments, the first and second coils are wired independently of each other, and the acoustic device further includes an electrical circuit which determines the change in the acoustic performance based on a change in the electrical output signal of the second coil.

The present invention is a signal processing circuit 12 for an electrostatic electroacoustic transducer configured to correct signals input to a single driven electrostatic electroacoustic transducer 15 including a diaphragm 151 and a fixed electrode 152 disposed to face the diaphragm. The signal processing circuit includes a correction value determiner 122 configured to determine a correction value v1 of a level based on a level of the input signals s1 from the sound source, and a level corrector 124 configured to correct the level of the input signals based on the correction value. The level corrector is configured to correct the level of an input signal among the input signals based on the correction value. The input signal corresponds to a signal for displacing the diaphragm to a first direction side on which a fixed electrode is not disposed with respect to a predetermined position.

The present invention is a signal processing circuit 12 for an electrostatic electroacoustic transducer configured to correct signals input to a single driven electrostatic electroacoustic transducer 15 including a diaphragm 151 and a fixed electrode 152 disposed to face the diaphragm. The signal processing circuit includes a correction value determiner 122 configured to determine a correction value v1 of a level based on a level of the input signals s1 from the sound source, and a level corrector 124 configured to correct the level of the input signals based on the correction value. The level corrector is configured to correct the level of an input signal among the input signals based on the correction value. The input signal corresponds to a signal for displacing the diaphragm to a first direction side on which a fixed electrode is not disposed with respect to a predetermined position.

A metamaterial loudspeaker diaphragm is disclosed. The diaphragm includes a cone structure having a periodic arrangement of two dissimilar materials, e.g., soft and hard, in an alternating periodic pattern to achieve an anisotropic structure, which results in passive amplification of the sound. The anisotropic cone structure includes a baseline cone material and a different, compatible second material. The cone includes a body having a conical cross-section, an interior side, an exterior side, and concentric circles of material alternating between a soft material and a rigid material. Circumferential grooves disposed within the concentric circles include rigid material. Concentric circles including rigid material line the interior side of the body. Substantially all the soft material of the concentric circles is disposed on the exterior side of the cone. Spokes disposed on the exterior side of the cone extend from a base toward a vertex of the cone.

A microelectromechanical system (MEMS) transducer includes a transducer substrate including an opening; a back plate including a plurality of protrusions oriented substantially perpendicular to the back plate; and a diaphragm between the transducer substrate and the back plate. The diaphragm includes a lead and a plurality of spring members. The lead is structured to suspend the diaphragm over the transducer substrate. The spring members are structured to separate the diaphragm from the transducer substrate and the back plate in the absence of a bias voltage.