Abstract: Provided is a microphone, including a base having a back cavity, a diaphragm, a backplate electrode, and a backplate spaced from the diaphragm and defining an inner cavity jointly with the diaphragm. The diaphragm includes a vibration portion, a fixing portion, and a leak hole. The back cavity is communicated with the inner cavity through the leak hole. The backplate is provided with a first through hole. The inner cavity is communicated with outside through the first through hole. The backplate includes a backplate body and a backplate extension portion. The inner cavity includes a first inner cavity and a second inner cavity. The backplate extension portion is provided with a second through hole, and the second inner cavity is communicated with outside through the second through hole. A method for manufacturing the microphone is further provided. The technical solution has better drop performance.

Abstract: A MEMS transducer system has a transducer configured to convert a received signal into an output signal for forwarding by a transducer output port, and an integrated circuit having an IC input in communication with the transducer output port. The IC input is configured to receive an IC input signal produced as a function of the output signal. The system also has a dividing element coupled between the IC input and the transducer output port. The dividing element is configured to selectively attenuate one or more signals into the IC input to at least in part produce the IC input signal. Other implementations may couple a feedback loop to the ground of the transducer (similar to bootstrapping), or pick off voltages at specific portions of the transducer.

Abstract: Presented herein are contaminant-proof microphone assemblies for use with devices/apparatuses, such as auditory prostheses, that include one or more microphones disposed within a housing. A contaminant-proof microphone assembly in accordance with certain embodiments presented herein includes a microphone, a microphone plug, and a contaminant-proof membrane. The microphone plug has a first end coupled to the microphone and a second end that is configured to be positioned adjacent the contaminant-proof membrane. As such, the microphone plug is disposed between a sound inlet of the microphone and the contaminant-proof membrane. The microphone plug may be configured to mate with the housing or a gasket attached to the housing.

Abstract: Method and apparatus for automatic gain control utilizing sound source position information in a shared space having a plurality of microphones and a plurality of sound sources. Sound signals are received from the microphones. One or more processors locate position information corresponding to each of the sound sources. The processor(s) determine the distance to each of the sound sources from each of the microphones. The processor(s) define a predetermined gain weight adjustment for each of the microphones. The processor(s) apply the defined weight adjustments to the microphones to achieve a consistent volume of the desired plurality of sound sources. The processor(s) maintain a consistent ambient sound level regardless of the position of the sound sources and the applied gain weight adjustments. The processor(s) output a summed signal of the sound sources at a consistent volume with a constant ambient sound level across the plurality of sound source positions.

Abstract: A condenser microphone with at least two microphone capsules, each including a diaphragm and a backplate. The backplates of both the first capsule and second capsule having an electret bias. The first capsule having a first polar pattern, and the second capsule having a second polar pattern. The second capsule having an external voltage bias that is continuously variable over a certain voltage range. This external voltage bias can be applied to the second diaphragm or second backplate. The microphone's total polar pattern consists of a combination of the first polar pattern and the second polar pattern. Using the external voltage bias of the second capsule, the microphone's total polar pattern is continuously variable throughout a range set by the external voltage bias.

Abstract: A remote microphone signal is obtained from a remote device, and a local microphone signal from a local device. A difference between strength of the remote microphone signal and strength of the local microphone signal is determined. An output audio signal is produced to drive a speaker in the local device. If the difference is greater than a threshold, then the local and remote microphone signals are applied to two input channels, respectively, of a two channel noise suppressor which produces the output audio signal, but if the difference is less than the threshold after a certain delay since the difference was greater than the threshold, then only the remote microphone signal is applied to a single input of a single channel noise suppressor which produces the output audio signal. Other aspects are also described and claimed.

Abstract: According to an example aspect of the present invention, there is provided a sound system, the sound system comprising: a first loudspeaker, comprising at least one first speaker element, a second loudspeaker, comprising at least one second speaker element, wherein the first and second loudspeaker have at least partially overlapping frequency ranges, and the first speaker is configured to produce a response within at least one first operating band defined within the frequency range of the first speaker, and the second speaker is configured to produce a response within at least one second operating band defined within the frequency range of the second speaker, and the first and second operating bands do not overlap, and wherein the overall response of the sound system at a first location is comprised of the response within the first operating band and the response within the second operating band.

Abstract: Embodiments relate to a circuit implementation for extending the bandwidth of an amplifier. The extended bandwidth amplifier includes an amplifier coupled between an input node and an output node of the extended bandwidth amplifier. The amplifier has an input capacitance and an output capacitance. The extended bandwidth amplifier additionally includes a first digitally-trimmable negative-capacitance capacitor coupled between the input node of the extended bandwidth amplifier and a power supply terminal. The digitally-trimmable negative-capacitance capacitor includes a first branch, a second branch, and a controller. The first branch includes a first capacitor having a first negative capacitance, and a first switch. The second branch includes a second capacitor having a second negative capacitance, and a second switch. The controller is configured to turn on the first switch and the second switch based on the input capacitance of the amplifier.

Abstract: The disclosure describes devices and methods for implementing impedance matching. The device may be implemented on an integrated circuit that includes a communication protocol interface circuit, a first signal output terminal, a first output driver circuit, and a controller. The first output driver circuit is coupled to the controller and has a corresponding plurality of parallel driver stages, each driver stage including a driver and a configurable resistance coupling an output of the driver to the first signal output terminal (e.g., first contact). The configurable resistances of the first output driver form a first series terminated resistance. The controller is configured to adjust the configurable resistances to adjust the first series terminated resistance.

Abstract: This disclosure provides methods, systems, and apparatuses, for a microphone. In particular, the microphone includes a housing having an external device interface with a plurality of contacts including a data contact. An electro-acoustic transducer is configured to generate an electrical signal in response to sound. An electrical circuit is coupled to contacts of the interface, the electrical circuit including an ADC having an input coupled to an output of the conditioning circuit and configured to convert the electrical signal to audio data after conditioning. A controller is configured to communicate data, other than the audio data, via the data contact of the external device interface during a start-up transition period of the microphone assembly, wherein the controller is configured to communicate the audio data via the data contact of the external device interface only after the start-up transition period is complete.

Abstract: Various embodiments of the present invention relate to a microphone, an electronic apparatus including the microphone and a method for controlling the microphone, the electronic apparatus comprising: a substrate comprising a first hole and a second hole into which an audio signal is input; a case that has a resonance space formed thereinside as a first side thereof is opened, a second side thereof is closed, and the first side is coupled with the substrate; a first audio generation unit that converts an audio signal input through a first hole of the substrate into an electrical signal, and comprises a first plate and a first membrane spaced apart from each other; a second audio generation unit that converts an audio signal input through a second hole of the substrate into an electrical signal, and comprises a second plate and a second membrane spaced apart from each other; a sound insulation wall that is disposed between the first audio generation unit and the second audio generation unit, and separates space

Abstract: According to one embodiment, a MEMS element includes a base body, a supporter, a film part, a first electrode, a second electrode, and an insulating member. The supporter is fixed to the base body. The film part is separated from the base body in a first direction and supported by the supporter. The first electrode is fixed to the base body and provided between the base body and the film part. The second electrode is fixed to the film part and provided between the first electrode and the film part. The insulating member includes a first insulating region and a second insulating region. The first insulating region is provided between the first electrode and the second electrode. A first gap is provided between the first insulating region and the second electrode. The second insulating region does not overlap the first electrode in the first direction.

Abstract: For manufacturing a sound transducer structure, membrane support material is applied on a first main surface of a membrane carrier material and membrane material is applied in a sound transducing region and an edge region on a surface of the membrane support material. In addition, counter electrode support material is applied on a surface of the membrane material and recesses are formed in the sound transducing region of the membrane material. Counter electrode material is applied to the counter electrode support material and membrane carrier material and membrane support material are removed in the sound transducing region to the membrane material.

Abstract: A system includes at least one earpiece wherein each earpiece comprises an earpiece housing, a light source operatively connected to each earpiece housing and configured to transmit substantially coherent light toward an outer surface of a user's body, a light receiver operatively connected to the earpiece housing proximate to the light source and configured to receive reflected light from the outer surface of the user's body, and one or more processors disposed within the earpiece housing and operatively connected to the light source and light receiver, wherein one or more processors is configured to determine bone vibration measurements from the reflected light. A method of determining bone vibrations includes providing at least one earpiece, transmitting substantially coherent light toward an outer surface of a user's body using the earpiece, receiving reflected light from the outer surface of the user's body using the earpiece, and determining bone vibration measurements using the earpiece.

Abstract: A MEMS transducer system has a transducer configured to convert a received signal into an output signal for forwarding by a transducer output port, and an integrated circuit having an IC input in communication with the transducer output port. The IC input is configured to receive an IC input signal produced as a function of the output signal. The system also has a dividing element coupled between the IC input and the transducer output port. The dividing element is configured to selectively attenuate one or more signals into the IC input to at least in part produce the IC input signal. Other implementations may couple a feedback loop to the ground of the transducer (similar to bootstrapping), or pick off voltages at specific portions of the transducer.

Abstract: An electromechanical pressure sensor system, in particular microphone type, including an electromechanical transducer, signal processing device, a substrate for receiving at least one support of the electromechanical transducer and/or signal processing device, a protective cover arranged on the upper face of the substrate, the support of the electromechanical transducer and/or signal processing device being housed in at least one cavity located on the lower face of the substrate is disclosed.

Abstract: An electrostatic transducer (100) comprises an electrically conductive backplane member (102) having an array of through apertures (112); a spacer member (104) disposed over the backplane member (102), the spacer member (104) having an array of holes (114) therethrough, the holes (114) each having a maximum lateral dimension less than twice a minimum lateral dimension; and a flexible electrically conductive membrane (106) disposed over the spacer member (104). The transducer (100) is arranged in use to apply an electrical potential which gives rise to an attractive electrostatic force between the backplane member (102) and the membrane (106) thereby moving portions of the membrane (106) spanning said holes in the spacer member (104) towards said backplane member (102).

Abstract: Provided is a microphone system insensitive to external noise, and the microphone system includes a microphone sensor that generates sensing data by sensing a change in sound pressure through a sensor bias voltage, a lead-out circuit that provides the sensor bias voltage for operating the microphone sensor, removes noise of the sensing data, and outputs the sensing data, a first pad that connects the microphone sensor and the lead-out circuit to each other and allows the sensor bias voltage to pass therethrough, and a second pad that connects the microphone sensor and the lead-out circuit to each other and allows the sensing data to pass therethrough.

Abstract: Various embodiments of the present technology may comprise methods and apparatus for controlling a bias voltage. Methods and apparatus for controlling a bias voltage to an electrical device according to various aspects of the present invention may comprise a voltage regulator circuit to generate a first voltage, a clock driver circuit to generate a second voltage, and a charge pump system to generate the bias voltage and supply the bias voltage to the electrical device. The apparatus may be responsive to a control signal that indicates a startup operation of the electrical device.

Abstract: A MEMS microphone includes a substrate, and a first conversion portion and a second conversion portion provided on the substrate, the first conversion portion and the second conversion portion convert sound into an electrical signal, the first conversion portion includes a first through hole, a first membrane covering the first through hole, and a first back plate facing the first membrane via a first air gap, the second conversion portion includes a second through hole, a second membrane covering the second through hole, and a second back plate facing the second membrane via a second air gap, and an area of the second membrane is 1.21 times or more and 2.25 times or less an area of the first membrane when viewed in a thickness direction of the substrate.

Abstract: In accordance with an embodiment, a MEMS microphone includes a sound detection unit having a first membrane, a second membrane arranged at a distance from the first membrane, a low-pressure region arranged between the first membrane and the second membrane, a gas pressure that is reduced in relation to normal pressure being present in said low-pressure region, a counter electrode arranged in the low-pressure region, and a sound through-hole, which extends through the sound detection unit in a thickness direction of the sound detection unit; and a valve provided at the sound through-hole, said valve being configured to adopt a plurality of valve states, wherein a predetermined degree of transmission of the sound through-hole to sound is assigned to each valve state.

Abstract: A MEMS capacitive sensor is disclosed. In an embodiment a MEMS capacitive sensor includes a capacitor having a variable capacitance, wherein the capacitor includes a backplate and a membrane being separated from each other by a variable distance, wherein the capacitor is arranged on a substrate, an output terminal configured to provide an output signal, wherein the output terminal is connected to the backplate, a bias voltage input terminal configured to apply a bias voltage, wherein the bias voltage input terminal is connected to the membrane and a supply voltage input terminal configured to apply a supply voltage, wherein the supply voltage input terminal is connected to the substrate, wherein the MEMS capacitive sensor is configured to generate a level of the output signal in dependence on the distance between the membrane and the backplate.

Abstract: A MEMS acoustic transducer provided with: a substrate of semiconductor material, having a back surface and a front surface opposite with respect to a vertical direction; a first cavity formed within the substrate, which extends from the back surface to the front surface; a membrane which is arranged at the upper surface, suspended above the first cavity and anchored along a perimeter thereof to the substrate; and a combfingered electrode arrangement including a number of mobile electrodes coupled to the membrane and a number of fixed electrodes coupled to the substrate and facing respective mobile electrodes for forming a sensing capacitor, wherein a deformation of the membrane as a result of incident acoustic pressure waves causes a capacitive variation of the sensing capacitor. In particular, the combfingered electrode arrangement lies vertically with respect to the membrane and extends parallel thereto.

Abstract: A Micro Electro Mechanical System (MEMS) microphone is provided. The MEMS microphone includes: a substrate including an audio hole and having an oxide layer at a predetermined segment along an upper surface edge; a vibration electrode that is supported by a support layer that is formed along an upper surface edge in a state that is separated to the inside of the center from the oxide layer at an upper portion corresponding to the audio hole; a fixed electrode that is formed at an upper portion of the oxide layer and in which one side of the support layer is bonded to one side of a low surface; and a back plate that is formed at an upper portion of the fixed electrode and in which the other side of the support layer is bonded to one side of a low surface.

Abstract: A phase correcting system for connection with a transducer. The phase correction may take place before amplifying the output of the transducer. The phase correction system comprises a circuit configured to low-pass filter an input and feed the output to the non-signal terminal of the transducer. This circuit may comprise a transconductance amplifier.

Abstract: A combo chip is provided. The combo chip is applicable to an USB connector, and includes an USB type-C circuit, an USB non-type-C circuit, a switch unit, and a mode control unit. The switch unit is connected to the USB type-C circuit and the USB non-type-C circuit, and the mode control unit is connected to a control terminal of the switch unit. After performing one or more mode determination procedures, the mode control unit controls the switch unit to connect the USB type-C circuit to a first pin and a second pin while disconnecting the USB non-type-C circuit from the first pin and the second pin, or otherwise controls the switch unit to connect the USB non-type-C circuit to the first pin and the second pin while disconnecting the USB type-C circuit from the first pin and the second pin.

Abstract: Microphone systems including a MEMS microphone and an electronic controller. The MEMS microphone includes a movable membrane and a backplate. The movable membrane includes a capacitive electrode and a piezoelectric electrode. The capacitive electrode is configured such that acoustic pressures acting on the movable membrane cause movement of the capacitive electrode. The piezoelectric electrode alters a mechanical property of the MEMS microphone based on a control signal. The backplate is positioned on a first side of the movable membrane. The electronic controller is electrically coupled to the piezoelectric electrode and is configured to generate the control signal.

Abstract: A microphone having a plural porous sound delay filter is provided. The microphone includes a housing that has a first sound passage, a second sound passage and a third sound passage. A sound element is disposed in a position that corresponds to the first sound passage in the housing, and a semiconductor chip is electrically connected with the sound element in the housing. A low frequency lag filter is disposed in the second sound passage and delays low frequency sound source and a high frequency lag filter is disposed in third sound passage and delays high frequency sound source.

Abstract: Detection of audible and ultrasonic signals is provided by a microelectromechanical microphone. The detection range of ultrasonic signals can be configurable. In certain embodiments, the microelectromechanical microphone can include a band-pass sigma-delta modulator that can generate a digital signal representative of an ultrasonic signal. In addition or in other embodiments, the microelectromechanical microphone can include an event detector device that can determine that an ultrasonic event has occurred and, in response, can send a control signal to an external device. Detection of ultrasonic signals can be utilized in vehicular applications and/or gesture recognition.

Abstract: A microphone assembly and a method for reducing a temperature dependency of a microphone assembly are disclosed. In an embodiment, the microphone assembly includes a transducer and a voltage supply for the transducer, wherein the voltage supply is configured to supply a temperature dependent voltage for reducing a temperature dependency of the microphone assembly.

Abstract: Various embodiments of the present technology may comprise methods and apparatus for controlling a bias voltage. Methods and apparatus for controlling a bias voltage to an electrical device according to various aspects of the present invention may operate in conjunction with a charge pump and a voltage regulator. A pulse generator may be employed to vary the output voltage of the voltage regulator, which in turn, varies the output voltage (bias voltage) generated by the charge pump. The pulse generator may be activated at the start-up of the electrical device.

Abstract: The disclosure relates to a microphone assembly including a multibit analog-to-digital converter configured to generate N-bit samples representative of a microphone signal. The microphone assembly also includes a first digital-to-digital converter configured to generate a corresponding M-bit digital signal based on N-bit digital samples, wherein N and M are positive integers and N>M. The microphone assembly may include a data interface configured to repeatedly receive samples of the M-bit digital signal and write bits of the M-bit digital signal to a data frame.

Abstract: A microphone and a method for operating a Microphone are disclosed. In an embodiment the microphone includes a transducer and a mode controller. The microphone has a normal operating mode (MO) and a collapse mode (M1). The mode controller switches to the collapse mode (M1) when an output signal of the transducer reaches or exceeds a predefined threshold value and switches to the normal operating mode (MO) when the output signal reaches or falls below a predefined further threshold value (S1).

Abstract: Systems and methods of sensing audio with a MEMS microphone that modulates a frequency of a phase-locked loop. The MEMS microphone includes a movable electrode and a stationary electrode. The phase-locked loop includes a voltage-controlled oscillator and a phase detector. The voltage-controlled oscillator includes a biasing circuit and a plurality of inverters. The biasing circuit is configured to generate a biasing signal based on a control signal. The plurality of inverters are configured to generate an oscillating signal based on the control signal and a capacitance between the movable electrode and the stationary electrode. The phase detector is configured to detect a phase difference between the oscillating signal and a reference signal. The phase detector is also configured to generate the control signal based on the phase difference. The controller is configured to determine an audio signal based on the control signal.

Abstract: Novel tools and techniques are provided for muting a microphone of an electronic device. In various embodiments, a muting device might include a headphone jack and a muting circuit. The headphone jack might include first, second, third, and fourth contacts, the first contact including a left line output contact, the second contact including a right line output contact, the third contact including a ground contact, and a fourth contact including a microphone contact. The muting circuit simulates an external microphone being connected to the headphone jack, without the microphone contact being connected to any microphone. In particular, when the headphone jack of the muting device is connected to the headphone port of a user device, the muting circuit might send a signal to the user device indicating that an external microphone is communicatively coupled to the headphone jack, thereby causing the built-in microphone of the user device to be deactivated.

Abstract: A removable condenser microphone assembly comprises a large-diaphragm condenser transducer having front and rear diaphragms; a cylindrical harness inside of which the transducer is mounted; a cylindrical ring inside of which the harness is mounted; a connector secured to the bottom of the ring configured to removably secure the microphone assembly to a body of a pencil microphone and to removably electrically couple the microphone assembly to pre-amp circuitry within the pencil microphone body; a switch secured to the ring; and a printed circuit board electrically coupled to the transducer and the switch and, in response to positions of the switch, separately control phantom power to the front and rear diaphragms of the transducer creating a plurality of selectable polar patterns of the transducer.

Abstract: A chamber that penetrates vertically is formed in a silicon substrate. A diaphragm is arranged on the upper surface of the silicon substrate so as to cover the upper opening of the chamber. Leg pieces are provided in corner portions of the diaphragm, within the diaphragm. The diaphragm and the leg pieces are separated by slits, and the leg pieces extend in the diagonal directions of the diaphragm. The leg pieces are connected to the diaphragm at the ends on the outer peripheral side of the diaphragm, and the ends on the central side of the diaphragm are supported by anchors provided on the upper surface of the silicon substrate. A back plate is provided above the silicon substrate so as to cover the diaphragm, and a fixed electrode plate is provided on the lower surface of the back plate so as to oppose the diaphragm.

Abstract: Provided is an acoustic transducer including: a semiconductor substrate; a vibrating membrane, provided above the semiconductor substrate, including a vibrating electrode; and a fixed membrane, provided above the semiconductor substrate, including a fixed electrode, the acoustic transducer detecting a sound wave according to changes in capacitances between the vibrating electrode and the fixed electrode, converting the sound wave into electrical signals, and outputting the electrical signals. At least one of the vibrating electrode and the fixed electrode is divided into a plurality of divided electrodes, and the plurality of divided electrodes outputting the electrical signals.

Abstract: A mixing console including a plurality of audio inputs and a plurality of audio processing channels. Control data is received from a microphone which is connected to a given audio input to provide audio data. The control data includes an indication of an audio source associated with a microphone. A router of the mixing console is configured to route the audio data from the given audio input to a given audio processing channel based on the received indication of the audio source.

Abstract: In an impedance converter using an electron tube as an active element, output impedance can be made sufficiently low, and the number of circuit elements therefor is decreased and a circuit configuration therefor is made simple. Provided is an impedance converter having an electron tube cathode-follower connected. The impedance converter includes a bias diode that provides a bias voltage to a cathode of the electron tube, high resistance elements that provide a voltage of the bias diode to a grid of the electron tube, a load circuit connected to the electron tube, and a complementary emitter output circuit including two transistors, respective bases of which are connected to one end and the other end of the bias diode.

Abstract: A system and method for performing microphone gating operations, is disclosed. The system and method include a transmitter configured to emit a transmit signal towards an object and a receiver configured to receive a reflected signal from the object, the reflected signal corresponding to the transmit signal. The system and method also include a controller configured to instruct the transmitter to emit the transmit signal and receive the reflected signal from the receiver. The controller is further configured to detect motion of the object based upon the reflected signal and turn a microphone on or off based upon the motion of the object.

Abstract: A headset includes a microphone that detects an acoustic signal, and converts the acoustic signal into a microphone signal, an audio processor that receives the microphone signal, and a twisted pair conductor element coupling the microphone and the audio processor. The twisted pair conductor element self-cancels a radio frequency (RF) field to prevent the RF field from entering the microphone.

Abstract: An audio jack may include two contacts to electrically connect to a ground contact of an audio plug in order to detect that a metallic audio plug is inserted into the audio jack. A first of these two contacts may be grounded to form a current return path that generates a ground voltage at the ground contact of the audio plug. The second of these two contacts may be repurposed after the detection to sense the ground voltage. The sensed ground voltage may be added to right and left audio signals. The net voltages provided to the audio plug may be right and left audio signals that include the sensed ground voltage minus the actual ground voltage at the ground contact of the audio plug. This may remove the ground voltage from the net audio output signals, which may reduce crosstalk.

Abstract: A method of detecting defects in a high impedance network of a MEMs microphone sensor interface circuit. The method includes adding a high-voltage reset switch to a high-voltage high impedance network, closing the high-voltage reset switch during a start-up phase of the MEMs microphone sensor interface circuit, simultaneously closing a low-voltage reset switch of a low-voltage high impedance network during the start-up phase, simultaneously opening the high-voltage reset switch and the low-voltage reset switch at the end of the start-up phase, and detecting a defect in the high-voltage high impedance network or the low-voltage high impedance network immediately after opening the high-voltage reset switch and the low-voltage reset switch.

Abstract: A condenser microphone utilizes a PLL circuit which includes a phase shift oscillator having an RC network that uses an electrostatic capacitance of the condenser microphone unit varying upon reception of a sound pressure and a resistance value of a variable resistance element; a phase detection unit that compares phases of a fixed frequency signal from a reference signal oscillator and an oscillation output signal from the phase shift oscillator and outputs a phase difference signal corresponding to a phase difference; a loop filter that extracts a control signal when receiving the phase difference signal from the phase detection unit; and a driver circuit that changes a resistance value of the variable resistance element provided in the phase shift oscillator based on the control signal obtained from the loop filter. The control signal obtained from the loop filter of the PLL circuit is used as an audio output signal.

Abstract: The present invention provides a microphone device capable of preventing a breakdown of a signal processor, which is provided in a circuit case, processing signals from a microphone unit accommodated in a unit case, and preventing production of noise in a state the unit case is detached from the circuit case. A microphone device 1 includes a unit case 3 accommodating a microphone unit 31, a circuit case 4 accommodating an input terminal receiving signals from the microphone unit, and a signal processor processing the signals input to the input terminal, the unit case 3 being detachably fixed to the circuit case 4, and a detector (38, 44) detecting the attachment or detachment between the unit case and the circuit case. The detector grounds the input terminal in response to the detection of the detachment of the unit case from the circuit case.

Abstract: An audio recording and playback device, of the present invention, capable of recording and playing back audio, comprises an audio input section for converting audio input during an audio recording operation into an electrical audio signal, a power feed section for carrying out power feeds to the audio input section by means of a balanced transmission line, an amplifier section for amplifying the audio signal, a boost section for generating a power feed voltage to be applied to the balanced transmission line and outputting to the power feed section, a output voltage changing section for carrying out control to vary the output voltage of the boost section, and a control section for controlling the power feed voltage of the power feed section by controlling the power feed section and the output voltage changing section.

Abstract: A microphone comprising an automatic bias control providing a better signal quality is proposed. The microphone comprises a bias control circuit that can provide two or more voltages to the microphone's capacitor. The bias control circuit increases the voltage if the collapse frequency is low and decreases the voltage if the collapse frequency is high.

Abstract: Methods and apparatus automatically cancel or attenuate an unwanted signal (such as low frequencies from wind buffets) from, and/or control frequency response of, a condenser microphone, or control the effective condenser microphone sensitivity before the signal reaches an ASIC or other processing circuit. As a result, the maximum amplitude signal seen by the processing circuit is limited, thereby preventing overloading the input of the processing circuit. Remaining (wanted) frequencies can be appropriately amplified to reduce the noise burden on further processing circuits. A corrective signal is applied to a bias terminal of the condenser microphone to cancel the unwanted signal. Optionally or alternatively, a controllable impedance is connected to a line that carries the signal generated by the MEMS microphone, so as to attenuate unwanted portions of the signal.

Abstract: Systems and methods of generating independent adjustable bias voltages for a differential microphone. The microphone system includes a positive adjustable charge pump, a positive sense capacitor, a negative adjustable charge pump, a negative sense-capacitor, and a differential amplifier. The positive adjustable charge pump is configured to generate a positive bias voltage. The positive sense-capacitor is configured to generate a positive sense voltage based on acoustic pressure from a first direction and the positive bias voltage. The negative adjustable charge pump is configured to generate a negative bias voltage. The negative sense-capacitor is configured to generate a negative sense voltage based on the acoustic pressure from the first direction and the negative bias voltage. The differential amplifier is configured to receive the positive and negative sense voltages. The differential amplifier is also configured to generate a differential voltage based on the positive and negative sense voltages.