A microphone system includes a microphone and a pre-amplification conditioning circuit configured within a housing and comprising a pair of matched JFETs configured in a differential pair with common-source configuration and, when biased, are operable to receive and amplify the differential microphone output signal. The microphone further includes a pair of BJTs configured as a complimentary feedback transistor pair with each of the pair of BJTs coupled in parallel to a corresponding one of the pair of matched JFETs, and a current sink coupled to the matched JFETs and corresponding emitter electrodes of the BJTs and operable to maintain a fixed total direct current through each of the matched JFETs and BJTs, which reduces the JFETs corresponding electrical load, reduces signal noise, and increases a maximum amplified microphone output signal level at the drains of the matched JFETs.

A variable voltage phantom power supply assembly includes a phantom power supply unit having a power input, and one or more audio channels. The variable voltage phantom power supply assembly also includes a variable voltage phantom power supply module having a phantom power supply circuit with a variable voltage controller and a variable voltage phantom power output. A method of customizing at least one performance characteristic of a microphone includes: modifying a phantom power supply to provide a variable voltage phantom power output; connecting a microphone to an input of a variable voltage phantom power supply assembly; adjusting the voltage output of the variable voltage phantom power supply to the microphone; monitoring the performance characteristics of the microphone; and, readjusting the voltage output of the variable voltage phantom power supply to the microphone to obtain at least one desired performance characteristic of the microphone.

A method and apparatus for detecting a photoacoustic light signal to prevent unauthorized voice commands for a microphone-controllable device are provided. The method includes receiving, by a processor, a signal, detecting, by the processor, that the signal is a photoacoustic signal generated by a thermal expansion and contraction of an object caused by at least one lightwave applied to the object, and activating, by the processor, a counter-measure to prevent the photoacoustic signal from reaching a microphone of a microphone-controllable device in response to detecting the photoacoustic signal.

A microphone may comprise a microphone element for detecting sound, and a digital signal processor configured to process a first audio signal that is based on the sound in accordance with a selected one of a plurality of digital signal processing (DSP) modes. Each of the DSP modes may be for processing the first audio signal in a different way. For example, the DSP modes may account for distance of the person speaking (e.g., near versus far) and/or desired tone (e.g., darker, neutral, or bright tone). At least some of the modes may have, for example, an automatic level control setting to provide a more consistent volume as the user changes their distance from the microphone or changes their speaking level, and that may be associated with particular default (and/or adjustable) values of the parameters attack, hold, decay, maximum gain, and/or target gain, each depending upon which DSP is being applied.

A piezoelectric sensor (e.g., for use in a piezoelectric MEMS microphone) includes a substrate and a cantilever beam attached to the substrate. The cantilever beam has a proximal portion attached to the substrate and extending to an unsupported distal end. An electrode is disposed on or in the proximal portion of the beam and has an outer boundary with a shape substantially corresponding to a contour line of a strain distribution plot for the cantilever beam resulting from a force applied to the cantilever beam.

A camera with image and audio capture capabilities is configured to protect the internal audio components from the external environment. The camera includes a housing that allows passage of sound waves via a port from an external area of the camera to an internal area of the camera. The camera includes a circuit board with an opening and a microphone attached to a first surface of the circuit board adjacent to the opening. The camera includes a compressible spacer attached to a second surface of the circuit board. The second surface of the circuit board may be diametrically opposite to the first surface. The camera includes a waterproof membrane between the housing and the compressible spacer.

Voice-controlled devices that include one or more speakers for outputting audio. In some instances, the device includes at least one speaker within a cylindrical housing, with the speaker aimed or pointed away from a microphone coupled to the housing. For instance, if the microphone resides at or near the top of the cylindrical housing, then the speaker may point downwards along the longitudinal axis of the housing and away from the microphone. By pointing the speaker away from the microphone, the microphone will receive less sound from the speaker than if the speaker were pointed toward the microphone). Because the voice-controlled device may perform speech recognition on audio signals generated by the microphone, less sound from the speaker represented in the audio signal may result in more accurate speech recognition, and/or a lesser need to perform acoustic echo cancelation (AEC) on the generated audio signals.

A method and apparatus for detecting a photoacoustic light signal to prevent unauthorized voice commands for a microphone-controllable device are provided. The method includes receiving, by a processor, a signal, detecting, by the processor, that the signal is a photoacoustic signal generated by a thermal expansion and contraction of an object caused by at least one lightwave applied to the object, and activating, by the processor, a counter-measure to prevent the photoacoustic signal from reaching a microphone of a microphone-controllable device in response to detecting the photoacoustic signal.

A hearing aid with wireless transmission function is disclosed, comprising a microphone for receiving an ambient sound and outputting it to an audio processing and hearing compensation module; the audio processing and hearing compensation module for processing the sound, amplifying and compressing the sound according to preset hearing compensation parameters, and outputting a processed sound signal to a sound generator (a loudspeaker); and functional control keys for adjusting land controlling various functions, such as adjusting volume, selecting listening program, answering phone, and turning on/off the disclosed. The audio processing and hearing compensation module of the disclosed processes and adjusts the sound according to preset hearing compensation parameters, an audio wireless transmission module is connected and fitted with an audio signal input end of the audio, processing and hearing compensation module, thereby replacing a complicated wired programming manner, realizing wireless fitting and greatly facilitating use by elderly users and hearing-impaired persons.

Systems and methods for automatic generation of labelled audio data are disclosed. The method is performed by an autonomous driving system (ADS) of an autonomous driving vehicle (ADV). The method includes recording a sound emitted by an object within a driving environment, and converting the recorded sound into audio data. The method further includes capturing at least one position of the object while the sound is being recorded. The method further includes automatically labelling the audio data using the captured at least one position of the object as an audio label, to generate labelled audio data, where the labelled audio data is utilized to subsequently train a machine learning algorithm to recognize a sound source during autonomous driving of the ADV.