Example systems, apparatus, and methods receive audio information including a plurality of frames from a source device, wherein each frame of the plurality of frames includes one or more audio samples and a time stamp indicating when to play the one or more audio samples of the respective frame. In an example, the time stamp is updated for each of the plurality of frames using a time differential value determined between clock information received from the source device and clock information associated with the device. The updated time stamp is stored for each of the plurality of frames, and the audio information is output based on the plurality of frames and associated updated time stamps. A number of samples per frame to be output is adjusted based on a comparison between the updated time stamp for the frame and a predicted time value for play back of the frame.

Example systems, apparatus, and methods receive audio information including a plurality of frames from a source device, wherein each frame of the plurality of frames includes one or more audio samples and a time stamp indicating when to play the one or more audio samples of the respective frame. In an example, the time stamp is updated for each of the plurality of frames using a time differential value determined between clock information received from the source device and clock information associated with the device. The updated time stamp is stored for each of the plurality of frames, and the audio information is output based on the plurality of frames and associated updated time stamps. A number of samples per frame to be output is adjusted based on a comparison between the updated time stamp for the frame and a predicted time value for play back of the frame.

A Bluetooth audio broadcasting system includes: an audio broadcasting device, a first Bluetooth member device, and a second Bluetooth member device. The audio broadcasting device broadcasts BLE audio packets. After the first Bluetooth member device issues a volume adjusting request, the audio broadcasting device transmits a volume adjusting instruction to the first Bluetooth member device and the second Bluetooth member device. The first Bluetooth member device acquires a predetermined audio data from the BLE audio packets, controls a first audio playback circuit to playback the predetermined audio data, and adjusts an audio volume of the first audio playback circuit according to the volume adjusting instruction. The second Bluetooth member device acquires the predetermined audio data from the BLE audio packets, controls a second audio playback circuit to playback the predetermined audio data, and adjusts an audio volume of the second audio playback circuit according to the volume adjusting instruction.

Volume leveler controller and controlling method are disclosed. In one embodiment, A volume leveler controller includes an audio content classifier for identifying the content type of an audio signal in real time; and an adjusting unit for adjusting a volume leveler in a continuous manner based on the content type as identified. The adjusting unit may configured to positively correlate the dynamic gain of the volume leveler with informative content types of the audio signal, and negatively correlate the dynamic gain of the volume leveler with interfering content types of the audio signal.

Devices, systems, and methods for multi-channel common-mode coupled alternating current (AC) gain amplifiers (MC-CM-AC Amp) are disclosed. The MC-CM-AC Amp can comprise a first operational amplifier including: a first non-inverting input port configured to be coupled to a first input signal, and a first inverting input port configured to be coupled to a first capacitor. The MC-CM-AC Amp can comprise a second operational amplifier including a second non-inverting input port configured to be coupled to a second input signal, and a second inverting input port configured to be coupled to a second capacitor. The MC-CM-AC Amp can comprise one or more gain-setting resistors configured to be coupled between the first capacitor and the second capacitor.

Disclosed are systems and methods for a variable-gain differentiator in series with at least two non-inverting amplifiers. The variable-gain differentiator is connected to a voltage-controlled source at its non-inverting input and to its output at its inverting input. The output is connected to the non-inverting input of the first non-inverting amplifier. The output of the first non-inverting amplifier is connected to the input of the second non-inverting amplifier. The output of the second non-inverting amplifier is connected to a series of three integrators. Each integrator is connected to its output by a feedback path. Varying the gain of the voltage-controlled amplifier varies the gain of the differentiator at the output of the third integrator, thereby varying the output of the system.

A light receiving unit receives a pulsed optical signal arriving from a search region. A branching unit generates, from a received light signal, a plurality of branch signals having signal intensities proportional to a signal intensity of the received light signal and different from one another. A conversion unit converts, from analog to digital, a signal fed via the individual path selected by a selection unit, and in accordance with a result of the conversion, a processing unit generates information regarding an object reflecting the optical signal. A control unit causes the selection unit to select one of the individual paths for which a determination unit determines that a magnitude of the fed signal is within an input range of the conversion unit and which provides the highest gain.

A light receiving unit receives a pulsed optical signal arriving from a search region. A branching unit generates, from a received light signal, a plurality of branch signals having signal intensities proportional to a signal intensity of the received light signal and different from one another. A conversion unit converts, from analog to digital, a signal fed via the individual path selected by a selection unit, and in accordance with a result of the conversion, a processing unit generates information regarding an object reflecting the optical signal. A control unit causes the selection unit to select one of the individual paths for which a determination unit determines that a magnitude of the fed signal is within an input range of the conversion unit and which provides the highest gain.

An integrated circuit includes an oscillator and a power amplifier. The oscillator includes a first node, a second node, and a network of one or more reactive components coupled between the first node and the second node. The power amplifier includes a first input coupled to the first output of the oscillator, a second input coupled to the second output of the oscillator, and an output. The power amplifier includes a coarse gain control circuit, a first amplifier stage, and a second amplifier stage.

An apparatus for noise reduction in audio signal processing includes a power amplifier, a zero-crossing detector, and a threshold detector. The power amplifier has an input signal terminal for receiving an audio input signal and an output signal terminal. The audio input signal is a digital-to-analog converted version according to a version of a digital audio signal. The power amplifier has an analog gain which is controllable in response to an analog gain control signal. The zero-crossing detector determines a zero-crossing detection signal according to an internal signal provided between the input signal terminal and the output signal terminal. The threshold detector determines a gain setting according to the digital audio signal and the zero-crossing detection signal to generate the analog gain control signal indicating the gain setting, wherein the threshold detector controls the analog gain of the power amplifier according to the analog gain control signal.