Abstract: Systems and methods are described by which microphones comprising a mechanical filter can be accurately calibrated to each other in both amplitude and phase.

Abstract: An apparatus comprising a capacitive transducer, for example a MEMS microphone. A first voltage generator is connected to receive a first voltage (VDD*) and generate a second voltage (VCP) for biasing the capacitive transducer. A control circuit is adapted to, in use, control the first voltage (VDD*) based on a calibration value, wherein a different calibration value would lead to a different first voltage level and the calibration value is set such that an input signal of known amplitude produces an output signal of predetermined amplitude.

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 signal processing circuit includes: an AD converter configured to quantize an input signal, whose amplitude changes in accordance with temperature, within a set voltage range and convert the quantized input signal into a digital signal; and a setting circuit configured to set the voltage range so as to be wider when the input signal is greater in amplitude in accordance with the temperature and so as to be narrower when the input signal is smaller in amplitude in accordance with the temperature.

Abstract: A switch control circuit monitors a signal produced by a MEMS or other capacitor microphone. When a criterion is met, for example when the amplitude of the monitored signal exceeds a threshold or the monitored signal has been clipped or analysis of the monitored signal indicates clipping is imminent or likely, the switch control circuit operates one or more switches so as to selectively connect one or more capacitors to a signal line from the microphone, i.e., so as to connect a selected capacitance to the signal line to attenuate the signal from the microphone and, therefore, avoid clipping. The switches may be MOSFET, MEMS or other types of switches co-located with the microphone in a common semiconductor package. Similarly, the capacitors, a circuit that processes the signals from the microphone and/or the switch control circuit may be co-located with the microphone in a common semiconductor package.

Abstract: This invention provides a condenser microphone unit having a diaphragm assembly in which a diaphragm does not attach to a fixed electrode even if a polarization voltage is increased. A condenser microphone unit is provided having a diaphragm assembly 1 in which a diaphragm 12 is stretched over a diaphragm support 10 and a fixed electrode 20 arranged to face the diaphragm assembly 1 through a spacer. An opening 10a over which the diaphragm 12 is stretched so as to be able to vibrate is formed in the diaphragm support 10, the diaphragm 12 is stretched over the diaphragm support 10 in a situation where a central part of the diaphragm is dented to be concave, and the concave is arranged to face the fixed electrode 20.

Abstract: The present invention relates to a condenser microphone assembly comprising an electro-acoustic transducer element comprising a diaphragm and a back plate, signal processing circuitry operatively connected to the transducer element so as to process signals generated by the transducer element, and a mode-setting circuitry for selectively setting the condenser microphone assembly in a test mode or an operational mode. The electro-acoustic sensitivity of the condenser microphone assembly, when operated in the test mode, is at least 40 dB lower than the corresponding electro-acoustic sensitivity of the assembly when operated in the operational mode. The present invention further relates to a method for determining a performance parameter of a signal processing circuitry mounted inside a housing of an assembled condenser microphone assembly.

Abstract: A method and an optical microphone that may include a transmitter; and a sensor; wherein the transmitter is arranged, when facing an external auditory canal of a user, to direct optical signals towards an area of the external auditory canal; wherein the sensor is arranged to generate sensing signals that are indicative of reflected radiation that reflected from the external auditory canal; wherein the reflected radiation conveys information about body conducted signals that propagate through a body of the user and cause the external auditory canal to vibrate.

Abstract: Disclosed is a system and method with independent adjustment of on and off-axis tonality and a system and method for modeling an idealized off-axis polar response of a directional microphone. The system can include two or more microphone capsules arranged in close proximity within a single housing and a filtering algorithm applied to the output of each microphone capsule that results in a signal that has a predominantly idealized on and off-axis user selectable polar pattern responses and user selectable microphone modeling which models the on-axis frequency response of a physical or virtual microphone. Optionally, the system and method can compensate for the on and off-axis polar response changes due to low-frequency proximity-effect.

Abstract: The present invention relates to a condenser microphone assembly comprising a capacitive electro-acoustic transducer element comprising a diaphragm and a back-plate operatively connected to a DC bias voltage, a fast charge pump adapted to generate the DC bias voltage, and a controllable or programmable current source operatively connected to the DC bias voltage to draw a predetermined DC current there from. The controllable or programmable current source is responsive to a difference between a representative of a detected DC bias voltage and a DC reference voltage.

Abstract: A push-pull-type electrostatic-type ultrasonic transducer includes a first electrode having through holes, a second electrode having through holes each of which is paired with the corresponding through hole of the first electrode, and an oscillation film sandwiched between a pair of the first and second electrodes and having a conductive layer to which direct current bias voltage is applied. When a wavelength obtained from a resonance frequency at a mechanical oscillation resonance point of the oscillation film is ?, a thickness t of the respective fixed electrodes is (?/4)·n or substantially (?/4)·n (where ?: wavelength of ultrasonic wave, n: positive odd number). AC signals as modulation waves produced by modulating carrier waves in an ultrasonic frequency band by signal waves in an audio frequency band are applied between a pair of the electrodes.

Abstract: A sound reproducing device includes parametric speakers disposed to a display, a loudspeaker, drivers, a human-body sensor, and a controller. The loudspeaker has a wider directivity than the parametric speakers. The drivers change directions of the parametric speakers, respectively. The parametric speakers and the drivers constitute at least two parametric speaker units each composed of respective one of the parametric speakers and respective one of the drivers. The controller reproduces sound information based the number of persons in front of the display detected from an output from the human-body senor. The sound reproducing device reduces the possibility for a number of persons to hear the sound noisily, and allows drawing more attention to the content, e.g. an advertisement.

Abstract: A driving circuit for a sound outputting apparatus includes a H-bridge and a charge pump established by six switches for driving two types of loudspeakers, respectively. The six switches include two common switches to be configured in the H-bridge and the charge pump, thereby reducing the costs and circuit area of the driving circuit.

Abstract: A speaker system includes a case defining a center hole and a body surrounding the center hole, an electroacoustic transducer received in the center hole of a case, and a microphone. The body of the case defines a sidewall, a bottom extending outwards from the sidewall, and a projecting element extending upwardly from the bottom and opposite to the sidewall. A slot is formed between the projecting element and the sidewall, and the microphone is positioned in the slot.

Abstract: The invention provides an audio interface device and method utilizing a single audio jack connector for plugging into a three-wire analog microphone or a three-wire digital microphone, thereby reducing dimensions and production costs thereof and an electronic system using the same. The audio interface comprises an audio jack connector, having first to third contacts electronically connected with the three-wire microphone plugged thereinto; and an audio processing device, detecting a type of the three-wire microphone plugged into the audio jack connector, outputting a clock signal to the three-wire microphone and receiving a digital audio signal from the three-wire microphone when the type is digital; or receiving analog audio signals from the three-wire microphone when the type is analog.

Abstract: A microphone circuit includes a capacitor capsule and first and second impedance converters connected differentially to the capacitor capsule. The microphone circuit includes first and second output buffer amplifiers connected differentially to the first and second impedance converters.

Abstract: A microphone system including an audio sensor with a first electrode and a second electrode. A voltage source is coupled to the first electrode and the second electrode. A high-impedance bias network is coupled between the voltage source and the first electrode of the audio sensor. Additional electronics operate based on a state of the first electrode of the electromechanical device. A feedback system is configured to maintain an electrical potential across the high-impedance bias network at approximately zero volts. Maintaining the electrical potential across the high-impedance bias network at approximately zero volts reduces the tendency of electrostatic pull-in occurring.

Abstract: A card reading apparatus for use with a personal handheld device is provided, wherein the personal handheld device has an audio socket for connecting with earphones or other corresponding devices. The card reading apparatus includes: a battery unit; a voltage stabilizer unit; a microcontrol unit; a contact terminal module; a digital-to-analog converter electrically connected to the microcontrol unit; an audio plug electrically connected to the digital-to-analog converter and removably connectable with the audio socket of the personal handheld device; and a mobile application program (APP) stored in a recording medium so as to be installed in the personal handheld device, wherein the mobile application program can interpret the data transmitted from the microcontrol unit through the digital-to-analog converter and the audio plug.

Abstract: A sound processing device includes: a plurality of sound input units; a detecting unit for detecting a frequency component of each sound input to the plurality of sound signal unit, the each sound arriving from a direction approximately perpendicular to a line determined by arrangement positions of two sound input units among the plurality of sound input units; a correction coefficient unit for obtaining a correction coefficient for correcting a level of at least one of the sound signals generated from the input sounds by the two sound input units so as to match the levels of the sound signals with each other based on the sound of the detected frequency component; a correcting unit for correcting the level of at least one of the sound signals using the obtained correction coefficient; and a processing unit for performing a sound process based on the sound signal with the corrected level.

Abstract: A MEMS microphone having an improved noise performance due to reduced DC leakage current is provided. For that, a minimum distance between a signal line of the MEMS microphone and other conducting structures is maintained. Further, a DC guard structure fencing at least a section of the signal line is provided.

Abstract: An external audio signal is input to an input terminal which is connected to the first terminal of a first resistor. The first terminal of a second resistor is connected to the second terminal of the first resistor. An operational amplifier is arranged such that its inverting input terminal is connected to the second terminal of the second resistor, and a reference voltage is applied to its non-inverting input terminal. A third resistor is arranged between the output terminal and the inverting input terminal of the operational amplifier. A first diode is arranged between the second terminal of the first resistor and a power supply terminal such that its cathode is on the power supply terminal side. Furthermore, a second diode is arranged between the second terminal of the first resistor and the ground such that its cathode is on the second terminal side of the first resistor.

Abstract: The present technology provides noise reduction of an acoustic signal using a configurable classification threshold which provides a sophisticated level of control to balance the tradeoff between positional robustness and noise reduction robustness. The configurable classification threshold corresponds to a configurable spatial region, such that signals arising from sources within the configurable spatial region are preserved, and signals arising from sources outside it are rejected. In embodiments, the configurable classification threshold can be automatically and dynamically adjusted in real-time based on evaluated environmental conditions surrounding an audio device implementing the noise reduction techniques described herein.

Abstract: A USB audio device includes a USB connector for connection to a general purpose computer, a USB controller connected to the USB connector for receiving an digitized audio signal from the computer and transmitting a digitized microphone signal and a controlling signal to the computer system, a digital/analog converter connected to the USB controller for processing the audio signal and the microphone signal and an earset socket connected to the digital/analog converter and having a left signal contact, a right signal contact, a ground contact, and a microphone signal contact.

Abstract: The invention provides an amplifier circuit of a capacitor microphone of which the noise resistance against noise of a supply voltage is enhanced. In an amplifier circuit of a capacitor microphone of the invention, while a noise component of a supply voltage is applied to one inversion input terminal of an operational amplifier of an amplification portion through a parasitic capacitor existing between an external power supply wiring and an external wiring that are adjacent to each other, the problem noise component of the supply voltage is applied to the other non-inversion input terminal by capacitive coupling to an internal power supply wiring. Therefore, the noise component is cancelled at the operational amplifier.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: A portable terminal includes an audio output unit configured to output audio signals to a plurality of external headphones; an event occurrence detection unit configured to detect occurrence of a predetermined event; and a control unit configured to, when the event occurrence detection unit detects the occurrence of the predetermined event while the audio output unit is outputting the audio signals to the plurality of external headphones, control the audio output unit to at least reduce the volume of an audio signal output to a particular external headphone specified in advance from among the plurality of external headphones to which the audio signals are output.

Abstract: There is disclosed a microphone, a circuit, and a method. A microphone capsule may include an electret microphone and a field effect transistor (FET). A floating DC voltage source may have a first end connected to a drain terminal of the electret microphone capsule and a second end. A load resistor may be connected between the second end of the floating DC voltage source and a source terminal of the electret microphone capsule. A voltage follower may have an output connected to the source terminal of the electret microphone capsule and the first end of the floating DC voltage source. A coupling capacitor may couple an audio signal from the source terminal of the electret microphone capsule to an input of the voltage follower.

Abstract: A signal from each of an array of microphones is analyzed. For at least one subset of microphone signals, a time difference is estimated, which characterizes the relative time delays between the signals in the subset. A direction is estimated from which microphone inputs arrive from one or more acoustic sources, based at least partially on the estimated time differences. The microphone signals are filtered in relation to at least one filter transfer function, related to one or more filters. A first filter transfer function component has a value related to a first spatial orientation of the arrival direction, and a second component has a value related to a spatial orientation that is substantially orthogonal in relation to the first. A third filter function may have a fixed value. A driving signal for at least two loudspeakers is computed based on the filtering.

Abstract: A signal processing apparatus includes a source separation module for producing respective separation signals corresponding to a plurality of sound sources by applying an ICA (Independent Component Analysis) to observation signals produced based on mixture signals from the sound sources, which are taken by source separation microphones, to thereby execute a separation process of the mixture signals, and a signal projection-back module for receiving observation signals of projection-back target microphones and the separation signals produced by the source separation module, and for producing projection-back signals as respective separation signals corresponding to the sound sources, which are taken by the projection-back target microphones. The signal projection-back module produces the projection-back signals by receiving the observation signals of the projection-back target microphones which differ from the source separation microphones.

Abstract: A stereo capacitor microphone unit includes: two unidirectional microphone units integrally formed with respective fixed electrodes of the unidirectional microphone units facing each other; and an insulating spacer that is interposed between the fixed electrodes and provided with a gap formed at a portion of an outer periphery towards radial direction. The gap communicates fixed electrode rear spaces of the respective unidirectional microphone units with an external space to serve as a common rear acoustic terminal for the unidirectional microphone units.

Abstract: Diaphragms of a plurality of capacitor microphone units are arranged in the same plane and the capacitor microphone units are connected in series to make an output from an impedance converter connected to one capacitor microphone unit drives a ground side of another capacitor microphone unit connected to the impedance converter.

Abstract: A circuit apparatus and a method for detecting an earphone in a portable terminal are provided. The apparatus includes an earjack, a first switch, a second switch, a comparator, and a main chip. The earjack outputs a signal informing whether an earphone is inserted, provides a signal input from a third pole of the inserted earphone to the first switch, and provides a signal input from a fourth pole to the second switch. The first switch outputs a signal provided from the earjack to one of a comparator and a ground depending on an input control signal. The second switch outputs a signal provided from the earjack to one of the comparator and the ground depending on the input control signal. The comparator compares a voltage of a signal provided from one of the first switch and the second switch with a reference voltage to output a signal representing a comparison result.

Abstract: An three-way audio system that uses directional arrays for radiating mid-frequency acoustic energy and passive directional devices to radiate the high frequencies. the system includes a left channel, a right channel, and a center channel. A crossover network separates the left channel and the right channel into low frequency content, midrange frequency content, and high frequency content. An omnidirectional acoustical device radiates acoustic energy corresponding to the low frequency content of the combined left channel, right channel and center channel. A first directional array, comprising signal processing circuitry and more than one acoustic driver, radiates acoustic energy corresponding to the midrange content of one of the left channel and right channel signal so that more acoustic energy corresponding to the midrange content of one of the left channel signal and the right channel signal is radiated laterally than in other directions.

Abstract: The present invention relates to a driver circuit wherein upper and lower legs of a first driver comprise first and second sets of parellelly coupled semiconductor switches, respectively. A control circuit is configured to generate respective control signals for the first and second sets of parellelly coupled semiconductor switches to create a current path through the upper and lower legs during an overlap time period between state transitions of a driver output.

Abstract: A stereo microphone includes a supporter that is made of an elastic material. The supporter fixes two unidirectional microphone units at certain angles. A moving part is used to apply external force to a part of the supporter so that an angle formed by main axes of the respective unidirectional microphone units is changed by deformation of the supporter.

Abstract: A system includes a plurality of inputs each configured to receive a filtered version of a source signal. The system extracts the energy information from each input signal and compares the energy information of a plurality of input signals. Alternatively, the system extracts energy information from a signal that is the difference of two input signals. Based on the energy information, the system determines at least one parameter that may be changed in at least one circuit in a plurality of circuits to minimize the differences in energy of the input signals or to minimize the energy of the difference signal. Parameters may include for example amplification, delay, and corner frequency values. The set of circuits may include microphone interface circuits. Merely by way of example, a system with microphone interface circuits may be included in a hearing enhancement device or in a hands-free earpiece.

Abstract: There is provided a capacitor microphone comprising a capacitor transducer (KW), a high frequency bridge (HFB) coupled to the capacitor transducer (KW), a high frequency coil (HFS) coupled to the high frequency bridge (HFB), an HF transformer (HFT), a synchronous demodulator (SD), a low frequency output (NFA) and a high frequency stabilizer unit (SE). The high frequency stabilizer unit (SE) is coupled between the synchronous demodulator (SD) and the low frequency output (NFA) and serves to stabilize the HF voltage.

Abstract: A semiconductor die with an integrated electronic circuit, configured so as to be mounted in a housing with a capacitive transducer e.g. a microphone. A first circuit is configured to receive an input signal from the transducer at an input node and to provide an output signal at a pad of the semiconductor die. The integrated electronic circuit comprises an active switch device with a control input, coupled to a pad of the semiconductor die, to operatively engage or disengage a second circuit interconnected with the first circuit so as to operate the integrated electronic circuit in a mode selected by the control input. That is, a programmable or controllable transducer. The second circuit is interconnected with the first circuit so as to be separate from the input node. Thereby less noise is induced, a more precise control of the circuit is obtainable and more advanced control options are possible.

Abstract: Systems and methods for a noise canceling microphone and microphone system are disclosed. The system generally includes a housing with a printed circuit board forming a surface of the housing. Electrical terminals are located on an exterior side of the printed circuit board. A diaphragm is disposed within the housing. A first port in the housing remote from the printed circuit board provides access to one face of the diaphragm first face and a second port disposed in the housing remote from the printed circuit board provides access to a second face of the diaphragm.

Abstract: The present invention provides a single wire programmable Micro Electromechanical System (MEMS) microphone and a programming method and system thereof. The single wire programmable MEMS microphone includes an MEMS sensor and an Application Specific Integrated Circuit (ASIC) chip connected to each other; the MEMS sensor is used for implementing acoustic-electric conversion; the ASIC chip includes an OUT interface, so that an upper computer judges, according to an output signal of the OUT interface, whether the ASIC chip is in a normal start mode or a programming mode, where if the output signal of the OUT interface is at a high level, the ASIC chip is in the normal start mode, and otherwise, the ASIC chip enters the programming mode.

Abstract: Push-to-talk audio devices and methods are provided. The audio device can include a tip-ring-ring-sleeve connector having a sleeve, tip, first ring, and second ring that are electrically isolated from each other. A microphone and a push-to-talk switch selectively operable to provide an electrical short across the microphone in a first state and to remove the electrical short from across the microphone in a second state are electrically coupled between the sleeve and the second ring.

Abstract: The present disclosure provides an electronic device with a remote control earphone electrically connected to the main body of the device. The remote control earphone includes seven sensing units, which are substantially arranged in a “8” shape. Sensing signal generated by each sensing unit in response to a touch from the user includes an identification code for identifying itself. The remote control earphone transmits the generated sensing signal to the main body. The main body includes a cache unit to store at least one identification code corresponding to the sensing signal, a storage unit to store the relationship between the identification codes and numbers the identification codes corresponding to, and a processing unit to determine which one of the numbers is input according to the at least one identification code and the relationship.

Abstract: First and second channel bridge amplifiers are dynamically configured to drive either speakers or headphones. The first channel bridge amplifier includes a first amplifier driving one end of a first speaker through a mechanical switch in a headphone-jack, and a second amplifier driving another end of the first speaker. The second channel bridge amplifier includes third and fourth amplifiers driving respective ends of a second speaker. To suppress click and pop, an amplifier control circuit maintains certain amplifiers (depending on headphone or speaker mode) tri-stated until input coupling capacitors have fully charged and an input signal exceeding a predetermined amount is detected.

Abstract: An integrated circuit includes at least one output cell including a first output cell having a ground pin connected to a ground rail, a first power supply pin connected to a first power rail, a second power supply pin connected to a second power rail, a data pin, at least one voltage select pin, and an output pin wired to the first output pad. The first output cell is configured to operate according to a first mode wherein the output pin has a first voltage amplitude, and according to a second mode wherein the output pin has a second voltage amplitude larger than the first voltage amplitude depending on a control signal applied to the at least one voltage select pin.

Abstract: A biasing circuit for an acoustic transducer is provided with: a voltage-booster stage, which supplies, on a biasing terminal, a boosted voltage for biasing a first terminal of the acoustic transducer; and filtering elements, set between the biasing terminal and the acoustic transducer, for filtering disturbances on the boosted voltage. The biasing circuit is further provided with switches, which can be actuated so as to connect the first terminal to the biasing terminal of the voltage-booster stage, directly during a start-up step of the biasing circuit, and through the filtering elements at the end of the start-up step.

Abstract: An audio amplifier (3) for a mobile telephone (1) is disclosed. The audio amplifier (3) comprises first and second output stages (11, 12), each for coupling to a respective one of first and second loudspeakers (4, 5), and switching circuitry (10) adapted to respond to a switching signal by switching an output signal from a common input stage (7, 8, 9) to the first output stage (11) when the switching signal is in a first state and to the second output stage (12) when the switching signal is in a second state.

Abstract: A video teleconferencing directional microphone includes three microphone elements arranged coincidentally on a vertical axis. The three microphone elements are placed on a supporting surface so that a first microphone element is on the surface, and the second and third microphone elements are elevated above the supporting surface. The directional microphone also includes three filters, a summing node, and an equalizer, which are used to shape the directivity pattern of the directional microphone into an elevated toroid sensitivity pattern. The elevated toroid sensitivity pattern increases sensitivity in the direction of a sound source of interest, but reduces sensitivity to any sound waves generated by noise sources at other locations.

Abstract: To provide a condenser microphone having a removable head unit on the microphone body, wherein the head unit can be attached and detached to and from the microphone body through one connection at a low impedance. A second pin 22h and a third pin 22c of a microphone body 20, which has a 3-pole output connector, is connected with current regulative diodes D2 and D3 as a feed circuit for the drain D of the FET Q1. A first AC coupling electrolytic capacitor C3 is connected to one of the current regulative diodes, D2, and a series circuit of a second AC coupling electrolytic capacitor C4 and a resistive element R3 is connected between the anode of the other current regulative diode D3 and a ground line L3. The resistive element R3 has substantially the same impedance as an output impedance of the transistor Q2.

Abstract: A micro-electromechanical (MEMS) based directional sound sensor includes a two sensor wings attached to a surrounding support structure by two legs. The support structure is hollow beneath the sensor wings allowing the sensor wings to vibrate in response to sound excitation. In one embodiment, interdigitated comb finger capacitors attached on the sensor wing edges and the support structure enable an electrostatic (capacitive) readout related to the vibrations of the sensor which allows determination of the sound direction.

Abstract: Direct digital speaker apparatus receiving a digital input signal and generating sound accordingly, the apparatus including: (a) an array of pressure-producing elements; and (b) a controller operative to compute a timing pattern determining if and when each pressure-producing element is actuated so as to achieve a desired directivity pattern; wherein said pressure-producing elements have the same amplitude.