Abstract: A control circuit for an electrostatic transducer including: an audio signal input, a detector configured to detect a current or charge signal from the electrostatic transducer. The detector is configured to produce an audio output signal varying at audio frequencies. A transform circuit is configured to transform the audio output signal to produce a feedback signal. A comparator is configured to compare an input audio signal at the audio signal input to the feedback signal to produce an error signal. A controller is configured to input a control signal to the electrostatic transducer, the control signal responsive to the error signal. The control signal is configured to control acoustic transparency of the electrostatic transducer, from outside space through through-holes of the first electrode, across the membrane and through through-holes of the second electrode.

Abstract: 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.

Abstract: A power amplifier includes an active device and an output matching circuit operably connected with the active device. The output matching circuit includes a bandpass impedance transformer, in particular, a multimode bandpass impedance transformer. The multimode bandpass impedance transformer may include a multimode resonator and coupling feed lines.

Abstract: Described are micro electrostatic transducers and methods of making such devices. The micro electrostatic transducer is an integrated component transducing device fabricated from materials allowing for low cost, high volume manufacturing. The device includes a sheet of graphene forming the diaphragm with two electrode layers above and below the diaphragm to introduce the audio signal.

Abstract: An improved compact electroacoustic transducer and loudspeaker system. The electroacoustic transducer (or array of electroacoustic transducers) can generate a desired sound by the use of pressurized airflow. The electroacoustic transducer does not have frames (unlike prior electroacoustic transducers) and an electrically conductive membrane is now supported by a pair of non-conductive vent members.

Abstract: An embodiment of the present invention provides an ultrasonic wave amplifying unit which can improve ultrasonic power in air, wherein the ultrasonic wave amplifying unit includes multiple rings having a concentric axis and each having a first width, and a slit having a second width is formed between the rings and an air layer is formed between the multiple rings and an ultrasonic wave generator generating ultrasonic waves or a transfer medium transferring the ultrasonic waves.

Abstract: This disclosure provides systems, methods, and device associated with an electrostatically driven graphene speaker. In one aspect, the device includes a graphene membrane having a diameter of about 3 millimeters to about 11 millimeters, and a first electrode proximate a first side of the graphene membrane, the first electrode being electrically conductive. The device is a microphone or a loudspeaker.

Abstract: The invention relates to an operator control apparatus for outputting haptic feedback comprising an operator control surface, an actuator, which is at least indirectly coupled to the operator control surface, for generating the haptic feedback on the operator control surface and a control unit which is designed to drive the actuator by means of a haptic component of a control signal for generating the haptic feedback. In this case, the control unit is designed to drive the actuator by means of an acoustic component of the control signal for generating acoustic feedback.

Abstract: A MEMS device includes a backplate electrode and a membrane disposed spaced apart from the backplate electrode. The membrane includes a displaceable portion and a fixed portion. The backplate electrode and the membrane are arranged such that an overlapping area of the fixed portion of the membrane with the backplate electrode is less than maximum overlapping.

Abstract: This disclosure provides systems, methods, and apparatus associated with an electrostatically driven graphene speaker. In one aspect, a device includes a graphene membrane, a first frame on a first side of the graphene membrane, and a second frame on a second side of the graphene membrane. The first frame and the second frame both include substantially circular open regions that define a substantially circular portion of the graphene membrane. A first electrode is proximate the first side of the circular portion of the graphene membrane. A second electrode proximate the second side of the circular portion of the graphene membrane.

Abstract: This disclosure provides systems, methods, and apparatus associated with an electrostatically driven graphene speaker. In one aspect, a device includes a graphene membrane, a first frame on a first side of the graphene membrane, and a second frame on a second side of the graphene membrane. The first frame and the second frame both include substantially circular open regions that define a substantially circular portion of the graphene membrane. A first electrode is proximate the first side of the circular portion of the graphene membrane. A second electrode proximate the second side of the circular portion of the graphene membrane.

Abstract: Disclosed is an acoustic transducer for converting a sound signal into an electric signal, including a mobile element movable under the effect of the sound signal, a fixed element opposite the mobile element, a recess, and a dissipative element between the mobile and fixed elements. The coupled system has a natural frequency corresponding to a resonance frequency of the transducer set at maximum sensitivity. The mobile element, the fixed element, the dissipative element and the recess are configured so the quality factor of the acoustic transducer>2. The recess has a straight prismatic, cylindrical, or frustoconical shape, the mobile element forming a first base of the prism, cylinder, or frustum, the fixed element being inside the prism, cylinder or frustum, over the second base of the prism, cylinder or frustum. Such a transducer also incorporates an analogue filtering function for filtering the signal around the natural frequency of same.

Abstract: This application relates to an apparatus (300) for monitoring an operating temperature condition of a microphone device (100) having an acoustic port (110). The apparatus includes a spectrum peak detect block (301) for receiving a microphone signal (SMIC) and determining, from the microphone signal, a resonance frequency (fH) and a quality factor (QH) of a resonance (202) associated with the acoustic port of the microphone. A condition monitoring block (302) is configured to determine any change in resonance frequency and quality factor with respect to respective reference values of resonance frequency and quality factor and to determine a temperature condition for the air temperature within the acoustic port based on said determined changes.

Abstract: An electrostatic transducer has two oppositely disposed counter-electrodes and a diaphragm which is disposed between the two counter-electrodes and which has a first weakly conductive coating. In its edge region the diaphragm has a second well-conductive coating on the first coating to protect the latter.

Abstract: A sensing system responsive to a wavefield of acoustic or seismic signals. In one embodiment, the system includes a frame having a surface of tubular shape about which a layer of piezoelectric material can be positioned to extend along a first direction. A piezoelectric element is positioned under tension to apply a force against the frame, which tension increases signal response of the element.

Abstract: A MEMS device includes a substrate, a supporter, a first back plate, a second back plate and a diaphragm. The substrate has a cavity. The supporter is over the substrate. The first back plate is over the cavity and fixed on the supporter. The second back plate is over the cavity and fixed on the supporter. The diaphragm is between the first back plate and the second back plate. The diaphragm includes a first sub-diaphragm and a second sub-diaphragm over the cavity and fixed on the supporter.

Abstract: The present invention provides a silicon speaker comprising an MEMS acoustoelectric chip and a PCB substrate, wherein the MEMS acoustoelectric chip comprises a corrugated diaphragm on a silicon substrate; and one side surface of the MEMS acoustoelectric chip is metalized, and the metalized side surface of the MEMS acoustoelectric chip is connected with the PCB substrate. The corrugated diaphragm is electrically conductive and interconnected with metal paths on MEMS acoustoelectric chip, which is led out to a first PCB metal path as one electrode. A second PCB metal path below the MEMS chip forms another electrode of the electrostatic actuator. The silicon speaker provided by the present invention lowers manufacturing costs of the speaker, and allows the diaphragm to generate high and repeatable/reliable sound pressure upon large displacements so as to improve the sounding effects of the speaker.

Abstract: An improved loudspeaker having pump cards that include an array of electrically conductive membrane transducers (such as polyester-metal membrane pumps). The array of electrically conductive membrane transducers combine to generate the desired sound by the use of pressurized airflow. The array of electrically conductive membranes has a total membrane area that is at least five times larger than the face area of the loudspeaker. In some embodiments, the loudspeaker includes a dynamic DC bus controller that maintains the DC bus level slightly above the inverter output (audio signal).

Abstract: Provided are methods and systems for enhancing the intelligibility of an audio (e.g., speech) signal rendered in a noisy environment, subject to a constraint on the power of the rendered signal. A quantitative measure of intelligibility is the mean probability of decoding of the message correctly. The methods and systems simplify the procedure by approximating the maximization of the decoding probability with the maximization of the similarity of the spectral dynamics of the noisy speech to the spectral dynamics of the corresponding noise-free speech. The intelligibility enhancement procedures provided are based on this principle, and all have low computational cost and require little delay, thus facilitating real-time implementation.

Abstract: A method and a system for achieving a self-adaptive surround sound.

Abstract: An apparatus includes a microelectromechanical system (MEMS) device having a diaphragm and a back plate; a clipping circuit coupled to the MEMS device, wherein the clipping circuit is configured to clip an output signal of the MEMS device so that the maximum signal drawn by a buffer is substantially constant over a temperature range; and an integrated circuit coupled to the clipping circuit, the integrated circuit including the buffer.

Abstract: An electrostatic ultrasonic transducer includes a first conductive layer; a second conductive layer spaced apart from the first conductive layer; and a third conductive layer disposed between the first and second conductive layers, the third conductive layer being spaced apart from the first conductive layer and in physical contact with a part of the second conductive layer.

Abstract: This disclosure relates to loudspeakers that use one or more stacks of electrically actuated cards that pump air through vents to produce sound waves in response to an acoustic signal. Each stack can include several electrostatic actuator cards that are stacked on top of each other and collectively operate to pump air through a vent to produce a sound wave. Each card may include an electrically conductive membrane that is pushed/pulled between two electrically conductive stators. As the membrane is pushed and pulled along a first axis, air is pumped through vents in a direction orthogonal to the first axis. In one embodiment, stacks of cards can be arranged in series to increase sound pressure generated by the loud speaker. In another embodiment, a single stack of cards can be driven with relatively high electric field strength to increase the sound pressure generated by the loud speaker.

Abstract: A dielectric for a capacitive-based tactile sensor of the type having a pair of spaced apart conductive plates with the dielectric conductively therebetween, includes a body of a non-rigid dielectric polymeric material. The body is shaped into a microstructure defined by a plurality of members adapted to extend from one of the conductive plates to the other. Some of the members includes a first feature shaped to have a first end surface and a second end surface. Second features are integral with the first feature and project from the second end surface. A cross-section area of each of the second features is substantially smaller than a cross-section area of the first feature at the second end surface. A height of the first feature in a distance between the conductive plates is substantially greater than a height of the second features. A capacitive-based tactile sensor with the dielectric is also provided.

Abstract: A dual diaphragm microphone can be used to reduce or eliminate a component of the output signal due to acceleration of the microphone. The dual diaphragm microphone can include a first sound-detecting component including a first diaphragm spaced apart from a first electrode and configured to generate a first signal and a second sound-detecting component including a second diaphragm spaced apart from a second electrode and configured to generate a second signal. The first sound-detecting component and the second sound-detecting component are oriented in opposite directions and include electronic circuitry configured to sum the first and second output signals to generate a combined output signal substantially unaffected by acceleration of the microphone.

Abstract: Embodiments herein describe an audio system that adjusts based on the location of a person. That is, instead of relying on fixed speakers, the audio system adjusts the direction of audio output for one or more speakers to optimize the performance of the audio system based on the location of a user or based on the number of users. To do so, the audio system may include a camera and a tracking application which identifies the location of a user and/or the number of users in front of the camera. Using this information, the audio system adjusts one or more actuators coupled to a speaker to change the direction of the audio output of the speaker. As the user continues to move or shift, the audio system can continually adjust the speaker to optimize the performance of the system.

Abstract: According to an embodiment, a microelectromechanical systems (MEMS) transducer includes a first electrode, a second electrode fixed to an anchor at a perimeter of the second electrode, and a mechanical support separate from the anchor at the perimeter of the second electrode and mechanically connected to the first electrode and the second electrode. The mechanical support is fixed to a portion of the second electrode such that, during operation, a maximum deflection of the second electrode occurs between the mechanical structure and the perimeter of the second electrode.

Abstract: An acoustic metamaterial including cells to digitally process an incoming sound waveform, and to produce a corresponding response sound waveform as a function of a frequency and a phase of the incoming sound waveform, to produce a total response sound waveform that, when combined with the incoming sound waveform, modifies the incoming sound waveform.

Abstract: The disclosure relates to a micro-electromechanical membrane arrangement with a substrate, which has a multiplicity of recesses on a surface, a first electrically conductive electrode layer, which is arranged on the surface of the substrate and has a multiplicity of first depressions coinciding with the recesses, and an electrically conductive membrane layer, which can be deflected in a direction perpendicular to the active surface of the substrate, is arranged over the first electrode layer and is kept at a distance therefrom by a first distance value.

Abstract: A hybrid ultrasonic audio system includes one or more ultrasonic speakers and one or more conventional speakers. An optical imaging system may be used to automatically determine the distance of a listener relative to the audio system. Channel processors apply distance-related transfer function filters to one or more of the audio channels based on the determined distances to equalize the amplitude of the audio played by the ultrasonic speakers relative to the conventional speakers. Channel processors may further apply a phase or time delay to the audio channels to match the phase and time delay of the ultrasonic speaker audio to the conventional speaker audio.

Abstract: A microelectromechanical system (MEMS) microphone has a substrate including a backside trench, and a flexible membrane deposited on the substrate extending over the backside trench. The flexible membrane includes a first electrode. A silicon spacer layer is deposited on a perimeter portion of the flexible membrane. The spacer layer defines an acoustic chamber above the membrane and the backside trench. A silicon rich silicon nitride (SiN) backplate layer is deposited on top of the silicon spacer layer extending over the acoustic chamber. The backplate defines a plurality of opening into the acoustic chamber and includes a metallization that serves as a second electrode.

Abstract: An electrostatic loudspeaker comprises a membrane structure and an electrode structure. The membrane structure comprises a central membrane portion and a circumferential membrane portion. The electrode structure is configured to electrostatically interact with the membrane structure for causing a movement of the membrane structure along an axis of movement. The electrode structure comprises a circumferential electrode portion and an opening, the circumferential electrode portion being substantially aligned to the circumferential membrane portion and the opening being substantially aligned to the central membrane portion with respect to a direction parallel to the axis of movement. In an end position of the movement of the membrane structure, the central membrane portion is configured to extend at least partially through the opening. A method for operating an electrostatic loudspeaker and a method for manufacturing an electrostatic loudspeaker are also described.

Abstract: A system and method for modulating the sound pressure that is output from an audio transducer is disclosed. In one embodiment, the method includes receiving an audio signal and placing the audio signal across a voice coil of the transducer. In addition, a voltage is applied across a field coil of the transducer, the field coil being separate from the voice coil. And the voltage that is applied across the field coil is adjusted so as to modulate the sound pressure output from the audio transducer.

Abstract: A parametric audio system having increased bandwidth for generating airborne audio signals with reduced distortion. The parametric audio system includes a modulator for modulating an ultrasonic carrier signal with a processed audio signal, a driver amplifier for amplifying the modulated carrier signal, and an array of acoustic transducers for projecting the modulated and amplified carrier signal through the air along a selected projection path to regenerate the audio signal. The acoustic transducer array includes a backplate having a succession of depressions formed thereon with at least one varying feature and/or dimension, and a membrane disposed along the backplate. The feature and/or dimension of the respective depressions vary so that the center frequencies of the respective acoustic transducers span a desired frequency range, thereby broadening the frequency response of the acoustic transducer array.

Abstract: A micro-speaker. The micro-speaker includes a first plate, a second plate, and a diaphragm. The first plate is biased to a first voltage. The second plate is biased to a second voltage. The diaphragm is positioned between the first plate and the second plate and is configured to receive a digital signal. The digital signal causes the diaphragm to cycle between fully displaced toward the first plate and fully displaced toward the second plate, creating air pressure pulses that mimic the digital signal.

Abstract: The invention is directed to systems, methods and computer program products associated with a microphone system for receiving a sound and producing an output signal representing the sound. The microphone system has a first microphone having a first dynamic range, the first microphone to receive the sound and produce a first sound signal based on the received sound. It also has a second microphone having a second dynamic range, the second microphone to receive the sound and produce a second sound signal based on the received sound, wherein the first dynamic range and the second dynamic range overlap thereby forming a transition dynamic range and processing logic operatively coupled to the first microphone and the second microphone. The processing logic is configured to receive the first sound signal from the first microphone, receive the second sound signal from the second microphone, and generate the output signal by combining the first sound signal and the second sound signal.

Abstract: The present invention discloses a driving circuit for electronic horn and a driving method for the electronic horn. The driving circuit includes an oscillating circuit, which generates a signal having oscillating frequency. Based on the signal, said driving circuit generates a driving signal to drive the electronic horn to produce sound. It is characterized in that said oscillating circuit includes a variable capacitor, and the oscillating frequency is changed by adjusting capacitance of the variable capacitor so as for the frequency of the driving signal to be consistent with working frequency of the electronic horn. The present invention overcomes the problem of mismatch between the frequency of circuit's driving signal and the horn's sounding diaphragm and horn's tone inflexion due to resistance change caused by vehicle vibration.

Abstract: A loudspeaker is described. The loudspeaker includes two or more segmentations of a planar radiator. Each of the segmentations has an associated frequency dependent velocity magnitude and phase with substantially uniform surface pressure. The two or more segmentations provide a substantially uniform radiation pattern across a wide range of acoustic frequencies. Apparatus, computer readable media and methods are also described.

Abstract: Provided is a method of manufacturing a loudspeaker including assembling a magnetic circuit and a frame. In the step of assembling the magnetic circuit and the frame, parallelism between a plate and a damper attachment portion of the frame is ensured by bringing an upper portion of the plate and the damper attachment portion of the frame into contact with a jig. In addition, perpendicularity between a magnetic gap and the damper attachment portion of the frame is ensured by bringing an outer circumferential side portion of the plate of the magnetic gap and an inner circumferential side portion of the yoke into contact with the jig. The magnetic circuit and the frame are assembled in such a state. With such a manufacturing method, it is possible to achieve a superior loudspeaker capable of reducing a gap defect while being downsized and having increased maximum input power.

Abstract: An electrostatic transducer loudspeaker includes a filterless class-D amplifier to modulate an audio input signal to generate a modulated signal containing a PWM switching carrier component, and a transformer directly connected at an output side of the filterless class-D amplifier and directly connected at an input side of an electrostatic transducer, whereby the equivalent capacitance of the electrostatic transducer and the equivalent inductance of the transformer establish a resonance circuit to demodulate the modulated signal to generate an AC voltage to drive the electrostatic transducer.

Abstract: The present invention discloses a flat speaker output device and a method for starting the same. Wherein, a plurality of flat speakers utilizes an initial delay unit and a plurality of intermediary delay units connected in series. The initial delay unit connects with the power controller and a first one of the flat speakers. The intermediary delay units respectively connect with the residual each flat speakers. The power controller controls a power source to the initial delay unit to delay the start of the first one of flat speakers, and outputs the power source to the intermediary delay units to sequentially delay the starts time of the residual each flat speaker. The present invention can sequentially start flat speakers without using a high-output power supply device and thus decrease the required capacity of the external power supply device.

Abstract: A backup alarm for producing an audible warning signal which warbles or beeps, at selected audible output power (Db) levels includes a computer which drives a speaker by switching drive voltage to the speaker with above audible, high frequency pulses in packets repetitive at audible frequency. The high frequency pulses are pulse width modulated at different ratios selected from tables in memory of the computer in accordance with the voltage from a battery power source which provides the drive voltage so that the audible output power remains constant at the selected level over a wide range of power source voltage. By providing for warning/alarm signal generation by means of an operating system which provides both high, above audible frequency and audible frequency switching, power conservation and warning signal output power control are accomplished without interference.

Abstract: A dual backplate MEMS microphone system including a flexible diaphragm sandwiched between two single-crystal silicon backplates may be formed by fabricating each backplate in a separate wafer, and then transferring one backplate from its wafer to the other wafer, to form two separate capacitors with the diaphragm.

Abstract: A driving interface device adaptive to a flat speaker is introduced herein. The driving interface device is coupled with an external sound source for receiving sound signals, and boosts voltage levels of the sound signals to drive the thin flat speaker without using an external power source. In one embodiment, an impedance component is provided in the driving interface device for coupling to the external sound source, so as to drive the flat speaker.

Abstract: A system and method for sensing acoustic sounds is provided having at least one directional sensor, each directional sensor including at least two compliant membranes for moving in reaction to an excitation acoustic signal and at least one compliant bridge. Each bridge is coupled to at least a respective first and second membrane of the at least two membranes for moving in response to movement of the membranes it is coupled to for causing movement of the first membrane to be related to movement of the second membrane when either of the first and second membranes moves in response to excitation by the excitation signal. The directional sensor is controllably rotated to locate a source of the excitation signal, including determining a turning angle based on a linear relationship between the directionality information and sound source position described in experimentally calibrated data.

Abstract: An electronic device includes a capacitance electro-acoustic transducer and an audio driver. The audio driver is coupled to the capacitance electro-acoustic transducer. The audio driver includes a high-voltage amplifier for receiving an input audio signal and for transforming the input audio signal into an output audio signal to drive the capacitance electro-acoustic transducer, wherein an absolute voltage value of the input audio signal is smaller than an absolute voltage value of the output audio signal. The output bandwidth of the capacitance electro-acoustic transducer is controlled by the magnitude of the output current of the audio driver. The capacitance electro-acoustic transducer of the present invention can meet different bandwidth requirements and thus achieve saving power, which cannot be achieved by a traditional dynamic electro-acoustic transducer.

Abstract: A sound-generating device comprises a first enclosure having at least one first electrode and a first piezoelectric layer, a first terminal of an audio signal output being coupled to the at least one first electrode of the first enclosure, a second enclosure having at least one first electrode and a first piezoelectric layer, and a first bendable element coupled between the first and second enclosures. The at least one first electrode is coupled with the first terminal of the audio signal output. The first piezoelectric layer of the first enclosure and the first piezoelectric layer of the second enclosure are configured to respond to the signal supplied by the audio signal output and to generate sound waves.

Abstract: An ultrasonic transducer having a reduced cost of manufacture. The ultrasonic transducer includes a first insulative retaining layer, a second insulative retaining layer, and a vibrator film layer sandwiched between the first and second retaining layers. The first retaining layer includes a first plurality of apertures formed therethrough, and the second retaining layer includes a second plurality of apertures formed therethrough, in which the second apertures are substantially in registration with the first apertures. The ultrasonic transducer further includes a first cover portion having a plurality of spring/backplate assemblies connected thereto, and a second cover portion. The combination of the first retaining layer, the vibrator film layer, and the second retaining layer is sandwiched between the first and second cover portions of the ultrasonic transducer.

Abstract: Methods are provided for production of pre-collapsed capacitive micro-machined ultrasonic transducers (cMUTs). Methods disclosed generally include the steps of obtaining a nearly completed traditional cMUT structure prior to etching and sealing the membrane, defining holes through the membrane of the cMUT structure for each electrode ring fixed relative to the top face of the membrane, applying a bias voltage across the membrane and substrate of the cMUT structure so as to collapse the areas of the membrane proximate to the holes to or toward the substrate, fixing and sealing the collapsed areas of the membrane to the substrate by applying an encasing layer, and discontinuing or reducing the bias voltage. CMUT assemblies are provided, including packaged assemblies, integrated assemblies with an integrated circuit/chip (e.g., a beam-steering chip) and a cMUT/lens assembly. Advantageous cMUT-based applications utilizing the disclosed pre-collapsed cMUTs are also provided, e.g.

Abstract: A digital sound system suitable for a digital speaker device for directly converting analog sound by a circuit using a ?? modulator and a mismatch shaping filter circuit to output a plurality of digital signals and a plurality of speakers driven by the plurality of digital signals. A digital speaker driving device includes a ?? modulator, a post filter, s driving circuits, and a power supply circuit to supply power to the ?? modulator, the post filter and the s driving elements and the s driving circuits are adapted to s digital signal terminals.