Abstract: Systems and methods for keyword detection using keyword repetitions are provided. An example method includes receiving an acoustic signal representing at least one captured sound. Using a keyword model, a first confidence score for the first acoustic signal may be acquired. The method also includes determining the first confidence score is less than a detection threshold within a first value. In response, lowering the threshold by a second value for a pre-determined time interval. The method also includes receiving a second acoustic signal captured during the pre-determined time interval and acquiring a second confidence score for the second acoustic signal. The method also includes determining the second confidence score equals or exceeds the lowered threshold, and then confirming keyword detection. The threshold may be restored after the pre-determined time interval. The keyword model may be temporarily replaced by a tuned keyword model to facilitate keyword detection in low SNR conditions.

Abstract: The disclosure relates to a microphone assembly comprising a multibit analog-to-digital converter configured to receive, sample, and quantize a microphone signal to generate N-bit digital microphone samples representative of the microphone signal at a first sampling frequency. The microphone assembly also comprises a first digital-to-digital converter configured to receive, quantize, and noise-shape the N-bit digital microphone samples to generate a corresponding M-bit Pulse Density Modulated (PDM) signal, wherein N and M are positive integers, and N>M. The microphone assembly may comprise a SoundWire compliant data interface configured to repeatedly receive samples of the M-bit PDM signal and write bits of the M-bit PDM signal to a SoundWire data frame.

Abstract: A receiver includes an acoustic module and a coil module. The acoustic module includes a first housing, a plurality of magnets, and an armature. The armature is disposed within the first housing and extends between the plurality of magnets. The coil module is coupled to the acoustic module, is physically separate from the acoustic module, and includes a second housing and a coil. The coil disposed within the second housing and does not surround the armature. The coil is excitable by an electrical current representative of acoustic energy and excitation of the coil produces a magnetic flux path which moves the armature.

Abstract: Systems, apparatuses, and methods for manufacturing a microelectromechanical system (MEMS) device. The MEMS device includes a substrate, a cap, a microelectromechanical component, and a tag. The substrate defines a port. The cap is coupled to the substrate. The substrate and the cap cooperatively define an interior cavity. The microelectromechanical component is disposed within the interior cavity and coupled to the substrate such that the microelectromechanical component is positioned over the port to at least partially isolate the port from the interior cavity. The tag is coupled to the substrate and the cap. The tag is positioned to secure the cap to the substrate.

Abstract: A microphone includes a base and a microelectromechanical system (MEMS) die mounted to the base. The microphone also includes an integrated circuit fixed to the base. The microphone further includes a lid mounted to the base that encloses the MEMS die and the integrated circuit within a cavity formed by the base and the lid. The lid has an indented portion extending into but not fully through the lid.

Abstract: A microphone assembly includes an acoustic transducer element configured to convert sound into a microphone signal in accordance with a transducer frequency response including a first highpass cut-off frequency. The microphone assembly additionally includes a processing circuit including a signal amplification path configured to receive, sample and digitize the microphone signal to provide a digital microphone signal. A frequency response of the signal amplification path includes a second highpass cut-off frequency which is higher than the first highpass cut-off frequency of the acoustic transducer element.

Abstract: A microphone device comprises a base, a port formed in the base, a cover attached to the base that forms a housing interior with the base, an MEMS element disposed in the housing interior and on top of the port, and an integrated circuit stacked on top of the MEMS element. The MEMS element includes a diaphragm and a backplate opposing the diaphragm. The integrated circuit includes an active surface and a substrate supporting the active surface. Circuitry and/or connectors are formed on the active surface for processing signals produced by the MEMS element. The substrate faces the MEMS element.

Abstract: At least one electrical value for a plurality of frequencies is measured over a range of frequencies. An impedance is calculated based upon the at least one electrical value for each of the plurality of frequencies in the frequency range, the calculating producing a plurality of impedances. A maximum impedance from the plurality of impedances and a frequency associated with the maximum impedance are determined. The frequency is compared to a predetermined threshold, and based upon the comparing it is determined whether an earphone has been removed from the ear of a wearer.

Abstract: An apparatus includes a coil; a stationary core, wherein the coil is wound about a portion the stationary core; a first magnetic structure and a second magnetic structure, wherein the first magnetic structure and the second magnetic structure are coupled to the stationary core; a first armature having a first end of the first armature and a second end of the first armature, wherein the first end of the first armature is coupled to the stationary core and the second end of the first armature is disposed within the first magnetic structure; and a second magnetic armature having a first end of the second armature and second end of the second armature, wherein the first end of the second armature is coupled to the stationary core and the second end of the second armature is disposed within the second magnetic structure.

Abstract: An integrated circuit includes a first amplifier and a second amplifier. A first impedance matching circuit is coupled to the first amplifier, a first charge pump, and a single MEMS transducer. A second impedance matching circuit is coupled to the second amplifier, a second charge pump, and to the single MEMS transducer. A first capacitive load as measured at an input of first amplifier, and a second capacitive load as measured at an input of the second amplifier exist. The first capacitive load and the second capacitive load are balanced with respect to each other. A single pressure change causes the single MEMS transducer to create a first electrical signal and a second electrical signal. Both the first electrical signal and the second electrical signal are matched or approximately matched in magnitude, and 180 degrees or approximately 180 degrees out of phase with respect to each other.

Abstract: A microphone includes a microelectromechanical system (MEMS) die configured to sense an acoustic signal, a base, and a lid. The base has a top surface and a bottom surface. The bottom surface includes a first electrical pad and a second electrical pad. The first electrical pad and the second electrical pad are configured to transmit an electrical signal indicative of the acoustic signal. The lid has a top surface and a bottom surface. The lid includes a cavity that surrounds the MEMS die. The top surface of the lid includes a third electrical pad and a fourth electrical pad. The first electrical pad and the third electrical pad are electrically connected, and the second electrical pad and the fourth electrical pad are electrically connected.

Abstract: A microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

Abstract: A microphone system includes a first transducer deployed at a first microphone; a second transducer deployed at a second microphone, the first microphone being physically distinct from the second microphone; a decimator deployed at the second microphone that receives first pulse density modulation (PDM) data from the first transducer and second PDM data from the second transducer and decimates and combines the first PDM data and the second PDM data into combined pulse code modulation (PCM) data; and an interpolator deployed at the second microphone for converting the combined PCM data to combined PDM data, and transmits the combined PDM data to an external processing device.

Abstract: A MOSFET active-disable switch is configured to clip an incoming signal in opposing directions when in an off state. By one approach the clipping is symmetrical and accordingly the switch clips both positive and negative peaks of the incoming signal. In many application settings it is useful for the clipping to serve to decrease a predetermined kind of resultant distortion such as even order distortion. In the on state this MOSFET active-disable switch is configured to not clip the incoming signal in opposing directions.

Abstract: A microphone device comprises a base, a port formed in the base, a cover attached to the base that forms a housing interior with the base, an MEMS element disposed in the housing interior and on top of the port, and an integrated circuit stacked on top of the MEMS element. The MEMS element includes a diaphragm and a backplate opposing the diaphragm. The integrated circuit includes an active surface and a substrate supporting the active surface. Circuitry and/or connectors are formed on the active surface for processing signals produced by the MEMS element. The substrate faces the MEMS element.

Abstract: An acoustic apparatus includes a back plate, a diaphragm, and at least one pillar. The diaphragm and the back plate are disposed in spaced relation to each other. At least one pillar is configured to at least temporarily connect the back plate and the diaphragm across the distance. The diaphragm stiffness is increased as compared to a diaphragm stiffness in absence of the pillar. The at least one pillar provides a clamped boundary condition when the diaphragm is electrically biased and the clamped boundary is provided at locations where the diaphragm is supported by the at least one pillar.

Abstract: A direct current (DC) bias maintenance circuit operably couples to the input of a primary amplifier. The DC bias maintenance circuit employs feedback to maintain the desired DC bias but lacks any coupling to the output of the primary amplifier. By one approach the DC bias maintenance circuit includes a secondary amplifier that replicates at least some near real-time performance characteristics of the primary amplifier. For example, the secondary amplifier can replicate at least certain DC properties of the primary amplifier such that DC-based changes appearing at the output of the primary amplifier are mirrored at an output of the secondary amplifier notwithstanding a lack of any coupling between the output of the primary amplifier and the DC bias maintenance circuit.

Abstract: Methods, systems, and apparatuses for preventing corrosion between dissimilar bonded metals. The method includes providing a wafer having a plurality of circuits, each of the plurality of circuits having a plurality of bond pads including a first metal; applying a coating onto at least the plurality of bond pads; etching a hole in the coating on each of the plurality of bond pads to provide an exposed portion of the plurality of bond pads; dicing the wafer to separate each of the plurality of circuits; die bonding each of the plurality of circuits to a respective packaging substrate; and performing a bonding process to bond a second, dissimilar metal to the exposed portion of each of the plurality of bond pads such that the second, dissimilar metal encloses the hole in the coating of each of the plurality of bond pads, thereby enclosing the exposed portion.

Abstract: Systems and methods for improving performance of a directional audio capture system are provided. An example method includes correlating phase plots of at least two audio inputs, with the audio inputs being captured by at least two microphones. The method can further include generating, based on the correlation, estimates of salience at different directional angles to localize a direction of a source of sound. The method can allow providing cues to the directional audio capture system based on the estimates. The cues include attenuation levels. A rate of change of the levels of attenuation is controlled by attack and release time constants to avoid sound artifacts. The method also includes determining a mode based on an absence or presence of one or more peaks in the estimates of salience. The method also provides for configuring the directional audio capture system based on the determined mode.

Abstract: A microphone device comprises a microphone die including a first microphone motor and a second microphone motor, an acoustic integrated circuit structured to process signals produced by the first microphone motor and the second microphone motor, and a sensor die stacked on top of the acoustic integrated circuit, wherein the sensor die comprises a pressure sensor. Another microphone comprises a microphone die including a first microphone motor and a second microphone motor and an integrated circuit die. The integrated circuit die comprises an acoustic integrated circuit structured to process signals produced by the first microphone motor and the second microphone motor, a pressure sensor, and a pressure integrated circuit structured to press signals produced by the pressure sensor.