The system includes an electronic device connected to a cord that can be unreeled and reeled in by a cord reel, and a management apparatus that can communicate with the electronic device. In the system, the cord-reel-use detector is disposed in the electronic device, and detects use of the cord reel. The memory is disposed in the electronic device and/or the management apparatus, and stores an amount of use of the cord reel. The controller is disposed in the electronic device and/or the management apparatus, and determines the use of the cord reel on the basis of the detection made by the cord-reel-use detector. The controller changes the amount of use of the cord reel in response to the electronic device having been replaced with another electronic device or in response to the cord reel having been replaced with another cord reel.

A method for eliminating unstable noise is provided and applicable to a sound recording device and implemented by a codec. The method includes: activating the sound recording device to start recording; setting a suppression duration and a cutoff frequency switching duration according to unstable noise and a DC offset value of the sound recording device; processing a front-end audio of a recorded sound by a filter having a first cutoff frequency to make the unstable noise in the front-end audio quickly converge, and outputting a filtered audio signal; suppressing the filtered audio signal according to the suppression duration to eliminate the unstable noise; and adjusting the first cutoff frequency of the filter to a second cutoff frequency according to the cutoff frequency switching duration, where the first cutoff frequency is greater than the second cutoff frequency. A device for eliminating unstable noise is also provided.

An apparatus for amplifying an audio source includes a speaker and a chip. The chip includes a processor configured to generate a signal and an amplifier element configured to amplify the signal into an amplified signal. The chip further includes a current monitor configured to monitor the current of the amplified signal prior to the amplified signal being output from the chip to the speaker and a voltage monitor configured to monitor the voltage of the amplified signal prior to the amplified signal being output from the chip to the speaker. The processor of the chip is configured to control a power of the amplified signal output from the chip to the speaker based at least on the current and the voltage.

In a speaker distortion correction device, an input signal passes through a nonlinear-portion correction filter and is input into a linear inverse filter. An output signal from the linear inverse filter is output into a speaker through an amplifier. For the nonlinear-portion correction filter, transfer characteristics (filter coefficients) are set that eliminate distortion due to nonlinear characteristics of the speaker. With a difference, as an error, between vibration of the speaker without distortion relative to an input signal and vibration of a vibration system of the speaker measured by a vibration measurement unit, an adaptive-algorithm execution unit performs an adaptive operation that adaptively updates filter coefficients of the linear inverse filter. When the amplitude of vibration of the vibration system of the speaker measured by the vibration measurement unit deviates from a range that normal relative to an input voltage input into the speaker, a control unit stops the adaptive operation of the adaptive-algorithm execution unit.

A device includes a readout circuit coupled between an input node and an output node; a microelectromechanical systems (MEMS) device coupled to the input node; and a first charge controlled clamp circuit coupled between the input node and a first bias node.

The present disclosure provides a current detection circuit for a loudspeaker 500, comprising a first detection resistor RSP, a second detection resistor RSN, a sampling selection circuit 100, an input selection circuit 200, and a processing circuit 300. By adding the sampling selection circuit 100 and the input selection circuit 200, voltages on two ends of the corresponding detection resistors (RSP, RSN) are sampled according to the fact that potential differences of an output stage VOP and an output stage VON of a class-D audio power amplifier 400 are in different semi-periods, and the current of the loudspeaker 500 is obtained through processing, thereby detecting the current of the loudspeaker 500 without adding an anti-clipping distortion function to the class-D audio power amplifier 400.

Example embodiments provide a process that includes one or more of receiving an audio signal at a feedback compressor circuit, multiplying the received audio signal with a power feedback signal to create a product audio signal, wherein the feedback signal comprises a low-pass filtered signal, applying a power amplifier to the product audio signal, and providing the amplified product audio signal as an output signal to a speaker.

Disclosed herein are system, apparatus, article of manufacture, method and/or computer program product embodiments, and/or combinations and sub-combinations thereof, for a wireless media system including a wireless speaker device and a host device forming a peer-to-peer wireless network. The host device provides audio content to the speaker device, and the speaker device can decode and process the audio content received from the host device. The speaker device can be in various states that consume different level of powers, such as a standby state, a wake state, a connected state. The speaker device can determine the host device is in an inactive state or an active state. When the speaker device determines the host device is in an inactive state, the speaker device can enter the standby state, enable the communication circuit and the audio processing circuit of the speaker device to be in a low power state to save power.

Apparatus, systems, articles of manufacture, and methods for volume adjustment are disclosed herein. An example method includes collecting data corresponding to a volume of an audio signal as the audio signal is output through a device, when an average volume of the audio signal does not satisfy a volume threshold for a specified timespan, determining a difference between the average volume and a desired volume, and applying a gain to the audio signal to adjust the volume of the audio signal to the desired volume, the gain determined based on the difference between the average volume and the desired volume.

Systems, methods, and apparatus for corona detection using audio data are provided. In one example embodiment, the method includes obtaining, by one or more computing devices, audio data indicative of audio associated with an electrical system for at least one time interval. The method includes partitioning, by the one or more computing devices, the audio data for the time interval into a plurality of time windows. The method includes determining, by the one or more computing devices, a signal indicative of a presence of corona based at least in part on audio data collected within an identified time window of the plurality of time windows relative to audio data collected for a remainder of the time interval.