Abstract: The problem of contaminants entering a microphone assembly through a pressure equalization aperture is mitigated by moving the pressure equalization aperture from a location near the acoustic port to a location on the cover of the microphone assembly. This is achieved by fabricating an aperture reduction structure using a separate dedicated die, with an aperture of diameter ˜25 microns or less disposed on the aperture reduction structure, and then coupling the aperture reduction structure to the cover of the microphone. The relatively smaller aperture on the cover after the coupling of the aperture reduction structure is used for pressure equalization of the back volume of the microphone with a pressure outside of the microphone assembly.

Abstract: An arrangement (2) to calibrate a capacitive sensor interface (1) includes a capacitive sensor (10) having a capacitance (cmem, cmemsp, cmemsm) and a charge storing circuit (20) having a changeable capacitance (cdum, cdump, cdumm). A test circuit (30) applies a test signal (vtst) to the capacitive sensor (10) and the charge storing circuit (20). An amplifier circuit (40) has a first input connection (E40a) coupled to the capacitive sensor (10) and a second input connection (E40b) coupled to the charge storing circuit (20). The amplifier circuit (40) provides an output signal (Vout) in dependence on a first input signal (?Verr1) applied to the first input connection (E40a) and a second input signal (?Verr2) applied to the second input connection (E40b). A control circuit (60) is configured to trim the capacitance (cdum, cdump, cdumm) of the charge storing circuit (20) such that the level of the output signal (Vout) tends to the level of zero.

Abstract: A hearing device includes a housing with a retention flange defining a retention space. A conduit is disposed about an electrical wire electrically coupled to a transducer and a ferrule is disposed about an end portion of the conduit and fixed along an axial dimension of the conduit, the ferrule having a portion disposable in the retention space. A bushing has a portion disposed at least partially about the portion of the ferrule disposable in the retention space, the bushing formed of a soft material relative to a hardness of the ferrule and the housing, wherein the bushing is located between the retention flange and the ferrule and the retention flange captures the conduit relative to the housing when the portion of the bushing is disposed in the retention space.

Abstract: Systems and apparatuses for a microelectromechanical system (MEMS) device. The MEMS device includes a housing, a transducer, and a sensor. The housing includes a substrate defining a port and a cover. The substrate and the cover cooperatively form an internal cavity. The port fluidly couples the internal cavity to an external environment. The transducer is disposed within the internal cavity and positioned to receive acoustic energy through the port. The transducer is configured to convert the acoustic energy into an electrical signal. The sensor is disposed within the internal cavity and positioned to receive a gas through the port. The sensor is configured to facilitate detecting at least one of an offensive odor, smoke, a volatile organic compound, carbon monoxide, carbon dioxide, a nitrogen oxide, methane, and ozone.

Abstract: A microphone assembly comprising: a housing including a base, a cover, and a sound port; a MEMS transducer element disposed in the housing, the transducer element configured to convert sound into a microphone signal voltage at a transducer output; and a processing circuit. The processing circuit comprising a transconductance amplifier comprising an input node connected to the transducer output for receipt of the microphone signal voltage, the transconductance amplifier being configured to generate an amplified current signal representative of the microphone signal voltage in accordance with a predetermined transconductance of the transconductance amplifier; and an analog-to-digital converter comprising an input node connected to receive the amplified current signal, said analog-to-digital converter being configured to sample and quantize the amplified current signal to generate a corresponding digital microphone signal.

Abstract: In accordance with one aspect, a device is provided having a transducer comprising a conductor, a diaphragm configured to move relative to the conductor, and a reference volume in communication with the external environment. The diaphragm separates the reference volume and the external environment. The device further includes a controller operably coupled to the transducer and configured to determine an air pressure of an external environment based at least in part on movement of the diaphragm.

Abstract: In one aspect, a low frequency driver is provided having a diaphragm operable to produce sound, a front volume, and an outlet that receives sound from the front volume and directs sound out from the low frequency driver. The low frequency driver further includes a low-pass filter chamber in communication with the front volume.

Abstract: An acoustic receiver employs one or more housing endplates recessed below an edge of a sidewall of the housing. In some implementations, a cured b-stage material is disposed in a recess along an interface between an endplate and a sidewall of the housing, wherein the cured b-stage material acoustically seals at least a portion of the housing. In some implementations, both a top housing endplate and a bottom housing endplate are recessed and have cured b-stage material disposed in respective recesses along an interface between the endplates and housing sidewalls wherein the cured b-stage material acoustically seals a top and bottom portion of the housing.

Abstract: A multi-core audio processor includes a data protocol interface configured to receive a stream of audio data, a plurality of data processing cores including a single sample processing core and a block data processing core, an audio fabric block configured to route samples of the stream between the data protocol interface and the plurality of data processing cores. The single sample processing core includes an execution unit configured to execute one or more low latency instructions for performing computations for the samples.

Abstract: A multi-core audio processor includes an audio fabric block configured to organize data received from a plurality of audio interfaces into streams for processing by a plurality of digital signal processing cores. The plurality of digital signal processing cores include a single sample processing core and a frame processing core. The multi-core audio processor also includes a pool of undedicated random access memory (RAM) and a main controller configured to dynamically allocate memory resources from the pool of undedicated RAM amongst one or more of the plurality of digital signal processing cores.

Abstract: An acoustic apparatus and method produces an acoustic signal in response to an electrical input signal applied to an acoustic receiver. The acoustic signal is converted to an electrical output signal that is proportional to a sound pressure of the acoustic signal, using an electro-acoustic transducer. In some embodiments the apparatus and method determine whether there is a change in the acoustic signal indicative of a change in an acoustic load coupled to the receiver by comparing the electrical output signal to reference information. The change in acoustic load, in one example, is attributable to ear wax accumulation in an output of the acoustic receiver or acoustic passage in the ear canal of a user or is attributable to seal leakage.

Abstract: The disclosure describes devices and methods of providing a DC bias voltage in a microphone assembly. Particularly, one implementation of such a device may be implemented on an integrated circuit that includes a direct current (DC) bias circuit. The DC bias circuit may be coupled to a transducer and configured to supply a DC bias signal to the transducer. The DC bias circuit includes a multi-stage charge pump and a low pass filter (LUFF) circuit. The multi-stage charge pump includes transistors that are fabricated with deep trench isolation (DTI).

Abstract: A multi-core audio processor includes a plurality of data ports configured to receive and transmit data, wherein a first data port of the plurality of data ports is configured to receive data associated with a first stream, a first plurality of audio interface resources configured to perform operations on the data, and a multiplexing unit configured to route data between the plurality of data ports and the first plurality of audio interface resources, the multiplexing unit including a multiplexer associated with each of the first plurality of audio interface resources. The multi-core audio processor also includes a first plurality of transport buffers, at least one transport buffer associated with each of the first plurality of audio interface resources. A first set of buffers of the first plurality of transport buffers is configured to synchronously store data received from the first set of the first plurality of audio interface resources.

Abstract: Disclosed herein include a system and a method of synchronizing a slave device to a signal from a master device based on pulse width analysis. The pulse width analysis is a process to sample the signal at a sampling frequency of the slave device, determine varying pulse widths of the sampled signal, and determine frequency of an embedded master clock signal of the signal based on statistical analysis of the varying pulse widths. Advantageously, performing pulse width analysis allows synchronization of a slave device with the embedded master clock signal in a time and cost efficient manner. In one aspect, determining a frequency of the embedded master clock signal and adjusting an internal clock of the slave device according to the determined frequency is faster and more cost efficient than iteratively adjusting the internal clock based on feedback loop based circuitries.

Abstract: A pre-distorted electrical excitation signal is generated for an acoustic transducer having an armature and a non-linear transfer characteristic by applying an electrical input signal (x) representative of a desired acoustic output to a computable non-linear function that is a function of the electrical input signal (x). When applied to an input of the transducer, the pre-distorted electrical excitation signal results in an improved acoustic output signal.

Abstract: The disclosure describes devices and methods for starting up a microphone assembly. The device may be implemented on an integrated circuit that includes a direct current (DC) bias circuit. The DC bias circuit may be coupled to a transducer and configured to supply a DC bias signal to the transducer. The DC bias circuit includes a multi-stage charge pump and a low pass filter (LPF) circuit. The LPF circuit includes an adjustable resistance and a capacitor. A resistance of the adjustable resistance may be reduced to reduce the settling time of the LPF while starting (e.g., turning on) the microphone assembly.

Abstract: A microphone assembly includes an acoustic filter with a first highpass cut-off frequency. The microphone assembly additionally includes a forward signal path and a feedback signal path. The forward signal path is configured to amplify or buffer an electrical signal generated by a transducer in response to sound and to convert the electrical signal to a digital signal. The feedback signal path is configured to generate a digital control signal based on the digital signal and to generate and output a sequence of variable current pulses based on the digital control signal. The variable current pulses suppress frequencies of the electrical signal below a second highpass cut-off frequency, higher than the first highpass cut-off frequency.

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 method in a transducer assembly having an external-device interface coupled to a communication protocol interface of the transducer assembly. The transducer assembly is configured to convert an input signal having one physical form to an output signal having a different physical form. At least two electrical signals are received on corresponding contacts of the external-device interface of the transducer assembly. A characteristic of at least one of the electrical signals is determined by evaluating a logic transition of the signal. A unique identity assigned to the transducer assembly is determined based on the characteristic.

Abstract: An electroacoustic transducer includes an armature that is mounted for deflection between magnets where an elongated portion of the armature includes a protrusion on opposite sides thereof for limiting the deflection of the armature. The protrusions are arranged transversely with respect to the elongated portion of the armature. Among other advantages, deflection of the armature is limited to provide improved shock performance. In one example, the protrusions are located within a magnet zone of the electroacoustic transducer.