Systems and methods for isolating audio content and biometric authentication include receiving, with an audio receiver, an audio signal spanning a plurality of frequency bands, identifying a speech signal carried by a voice frequency band selected from the plurality of frequency bands, enhancing the speech signal relative to other audio content within the audio signal, and extracting a voice profile key that uniquely identifies the speech signal, wherein enhancing the first speech signal comprises adjusting attack and release times of the speech signal based on sound events within the speech signal, the attack time being associated with very high frequency sounds that are not phase-shifted.

A switching amplifier includes a first portion of a power stage; a second portion of a power stage; a pulse-width modulation (PWM) control loop coupled to control inputs of the first portion of the power stage; and a linear amplifier coupled to control inputs of the second portion of the power stage. The PWM control loop controls a first switch and a second switch of the first portion of the power stage. Between current terminals of the first switch and the second switch is a first signal output of the switching amplifier. The linear amplifier controls a third switch and a fourth switch of the second portion of the power stage. Between current terminals of the third switch and the fourth switch is a second signal output of the switching amplifier.

An IC for power conversion includes bias circuitry that generates one or more bias voltages. An adaptive biasing circuit adaptively shifts an input signal having a negative value to a positive value. An operational transconductance amplifier (OTA) receives a supply bias current and the first and second bias voltages. The OTA has first and second input terminals coupled to the input signal and ground, respectively. The OTA has first and second transistors coupled to the first and second input terminals through first and second resistors at first and second internal nodes, respectively. Additional circuitry of the OTA is coupled to the second internal node. The additional circuitry insures that the voltage at the second internal node follows the voltage at the first internal node. The OTA generates an output current signal responsive to a differential input voltage applied across the first and second input terminals.

An IC for power conversion includes bias circuitry that generates one or more bias voltages. An adaptive biasing circuit adaptively shifts an input signal having a negative value to a positive value. An operational transconductance amplifier (OTA) receives a supply bias current and the first and second bias voltages. The OTA has first and second input terminals coupled to the input signal and ground, respectively. The OTA has first and second transistors coupled to the first and second input terminals through first and second resistors at first and second internal nodes, respectively. Additional circuitry of the OTA is coupled to the second internal node. The additional circuitry insures that the voltage at the second internal node follows the voltage at the first internal node. The OTA generates an output current signal responsive to a differential input voltage applied across the first and second input terminals.

An audio processing apparatus includes an audio input unit configured to input a plurality of audio signals, a reduction unit configured to reduce the amount of wind noise in the plurality of input audio signals, and a controller configured to control the reduction amount of the wind noise by the reduction unit based on a difference between an in-phase component and an antiphase component of the plurality of audio signals and control the speed of change of the reduction amount of the wind noise by the reduction unit based on a magnitude of the in-phase component of the plurality of audio signals. The audio processing apparatus reduces the adverse effects of the wind noise reduction process on the audio quality of the audio signals.

In one example, an apparatus comprises a control circuit, a first power stage, and a second power stage. The control circuit has an input, first control outputs, and second control outputs, the control circuit including a modulated signal generator coupled between the input and the first control outputs and an amplifier coupled between the input and the second control outputs. The first power stage has first control inputs and a first power stage output, the first control inputs coupled to the first control outputs. And the second power stage has second control inputs and a second power stage output, the second control inputs coupled to the second control outputs.

Systems and methods described herein modify audio content on an electronic device. Embodiments can be configured to detect a mode of the electronic device to determine whether the device is in a telephone mode; receive a speech signal from a speech source while the device is in the telephone mode; and process the speech signal to improve the perceived quality of the speech at a recipient when the electronic device is in a telephone mode; wherein processing the speech signal to improve the perceived quality of the speech comprises, decreasing the signal level of audio content outside of a determined frequency band relative to the signal level of the audio content within the determined frequency band; and wherein the determined frequency band is a frequency band associated a vocal range of the anticipated speech content. The method further includes adjusting high frequency sounds such as attack and release times of the speech signal based on sound events within the speech signal.

A system may include control circuitry for detecting a plosive event associated with a microphone transducer and in response to the plosive event, causing restoration of acoustic sense operation of the microphone transducer and a processing circuit associated with the microphone transducer. A system for configuring a filter having at least two frequency response configurations to achieve an effective frequency response configuration intermediate to the at least two frequency response configurations may include control circuitry for rapidly switching between the at least two frequency response configurations such that a weighted average frequency response of the filter corresponds to the effective frequency response configuration.

A system may include control circuitry for detecting a plosive event associated with a microphone transducer and in response to the plosive event, causing restoration of acoustic sense operation of the microphone transducer and a processing circuit associated with the microphone transducer. A system for configuring a filter having at least two frequency response configurations to achieve an effective frequency response configuration intermediate to the at least two frequency response configurations may include control circuitry for rapidly switching between the at least two frequency response configurations such that a weighted average frequency response of the filter corresponds to the effective frequency response configuration.

A system may include control circuitry for detecting a plosive event associated with a microphone transducer and in response to the plosive event, causing restoration of acoustic sense operation of the microphone transducer and a processing circuit associated with the microphone transducer. A system for configuring a filter having at least two frequency response configurations to achieve an effective frequency response configuration intermediate to the at least two frequency response configurations may include control circuitry for rapidly switching between the at least two frequency response configurations such that a weighted average frequency response of the filter corresponds to the effective frequency response configuration.