Provided is an electronic device for controlling surface heart and a method of controlling the electronic device. The electronic device includes a speaker, a temperature sensor, a memory, and a processor electrically coupled to the speaker, the temperature sensor, and the memory. The processor obtains first temperature information based on impedance information measured in a coil included in the speaker; obtains second temperature information measured by the temperature sensor, the second temperature information based on a heat source disposed adjacent to the speaker; predicts a surface temperature of a surface area of the electronic device, opposite to an internal area in which the speaker is disposed, based on the first temperature information and the second temperature information using a nonlinear approximation function; and controls an audio signal input to the speaker based on the predicted surface temperature.

The present teachings relate to an electronic device comprising: a first module for generating an audio signal; a second module for generating an ultrasonic signal; a mixer for generating a combined signal; a transmitter for outputting an acoustic signal dependent upon the combined signal; and, a processing means for controlling the ultrasonic signal; wherein, in response to receiving a first instruction signal for initiating the ultrasonic signal, the processing means is configured to increase the amount of the ultrasonic signal in the combined signal from an essentially zero value to a predetermined value over a predetermined enable time-period. The present teachings also relate to an electronic device configured to decrease the amount of the ultrasonic signal in the combined signal from an essentially zero value to a predetermined value over a predetermined disable time-period, and to an electronic device configured to remove the audio signal from the combined signal whilst preventing pop-noise, and to an electronic device capable of replacing the ultrasonic signal whilst minimizing the processing time. The present teachings further relate to a method for reducing the occurrence of pop noise in an acoustic signal associated with: initiating the ultrasonic signal in the combined signal, terminating the ultrasonic signal in the combined signal, terminating the audio signal in the combined signal, and replacing the ultrasonic signal in the combined signal. The present teachings also relate to a computer software product for implementing any of the method steps disclosed herein, and to a computer storage medium storing the computer software herein disclosed.

A protection and attenuation circuit for sensitive AC loads is described. The circuit provides AC power protection and attenuation utilizing high-efficiency switch-mode techniques to attenuate an AC power signal by incorporating a bidirectional, transistorized switch driven from a pulse width modulation signal, PWM. The circuit monitors characteristics of the AC power signal driving a known load and characteristics of the load or other elements and determines the duty cycle of the pulse width modulated signal, PWM, based upon the duration and amplitude of the over-voltage, over-current, over-limit or other event.

This application describes methods and apparatus for loudspeaker protection. A loudspeaker protection system (100) is described having a first frequency band-splitter (102) for splitting an input audio signal (Vin) into a plurality of audio signals (v1, v2 . . . , vn) in different respective frequency bands (ω1, ω2 . . . , ωn). A first gain block (103) is configured to apply a respective frequency band gain (g1, g2 . . . , g3) to each of the audio signals in the different respective frequency bands and a gain controller (107, 108, 109) is provided for controlling the respective band gains. A displacement modeller (104, 105) determines a plurality of displacement signals (x1, x2 . . . , xn) based on the input audio signal (Vin) and a displacement model (104a) where each displacement signal corresponds to a modelled cone displacement for the loudspeaker for one of said different respective frequency bands. The gain controller (107, 108, 109) is configured to control the respective frequency band gains based on the plurality of displacement signals.

Brownout management for an audio amplification system. An audio amplification system includes audio volume control circuitry, audio sample interpolation circuitry, and brownout management circuitry. The brownout management circuitry includes brownout detection circuitry and brownout response circuitry. The brownout detection circuitry is configured to determine whether a voltage of a battery that powers the audio amplification system is below a brownout threshold, and to generate a brownout detection signal that indicates the voltage is below the brownout threshold. The brownout response circuitry is coupled to an audio output of the audio sample interpolation circuitry. The brownout response circuitry is configured to attenuate the audio samples output by the audio sample interpolation circuitry responsive to the brownout detection signal indicating that the voltage is below the brownout threshold.

A class-D amplifier includes measurement of speaker current via the low-side drive transistors of the amplifier. In one embodiment, a class-D amplifier includes two high-side transistors, two low-side transistors, a first sense resistor, a second sense resistor, and a sigma delta analog to digital converter (σΔ ADC). The two high-side transistors and two low-side transistors are connected as a bridge to drive a bridge tied speaker. The first sense resistor is connected between a first of the low-side transistors and a low-side reference voltage. The second sense resistor is connected between a second of the low-side transistors and the low-side reference voltage. The ΣΔ ADC is coupled to the bridge to measure voltage across the first sense resistor and the second sense resistor.

A sound emitting device includes a speaker box, a loudspeaker, a temperature sensor, a central processing unit and a signal amplifier. The speaker box includes a sound hole. The temperature sensor detects a temperature of the sound emitting device and generates a detection signal. The central processing unit pre-stores a default audio signal. When the central processing unit determines that the loudspeaker is in a standby state and the temperature of the sound emitting device exceeds a threshold value, the central processing unit issues the default audio signal. The signal amplifier is connected to and disposed between the central processing unit and the loudspeaker for amplifying the default audio signal and transmitting the amplified default audio signal to the loudspeaker. A vibration diaphragm of the loudspeaker undergoes a vibration action according to the amplified default audio signal.

A read circuit for capacitive sensors such as a MEMS microphones includes a sensor node configured to be coupled to a capacitive sensor to apply a bias voltage to the sensor and sense the capacitance value of the sensor wherein the voltage at the sensor node is indicative of the capacitance value of the capacitive sensor. A switch is provided between the sensor node and the intermediate node. A shock detector coupled to the sensor node and the switch asserts a shock signal to make the switch conductive in response to a shock applied to the capacitive sensor, and de-asserts the shock signal to make the switch non-conductive with a delay after the end of the shock applied to the capacitive sensor.

In some embodiments, a method for performing at least one of enhancement, decoding, or rendering of a multichannel audio signal in response to compression feedback or feedback from a smart amplifier. For example, the compression feedback may be indicative of amount of compression applied to each of multiple frequency bands, of the audio signal or an enhanced audio signal generated in response thereto. The enhancement (e.g., bass enhancement) may include dynamic routing of audio content of the input audio signal between channels of an enhanced audio signal generated in response thereto. The enhancement and compression may be performed on a per speaker class basis. Other aspects are systems (e.g., programmed processors) and devices (e.g., devices having physically-limited bass reproduction capabilities, such as, for example, a notebook or laptop computer, tablet, soundbar, mobile phone, or other device with small speakers) configured to perform any embodiment of the method.

A system and method can provide nose, such as wind noise, mitigation and/or microphone blending. Some methods may include sampling a sound signal from a plurality of microphones to generate a frame comprising a plurality of time-frequency tiles of the sound signal, each time-frequency tile including respective values of at least one feature from the plurality of microphones, comparing the respective values of the at least one feature to determine whether each time-frequency tile satisfies a similarity threshold, and flagging each time-frequency tile as noise if it fails to satisfy the similarity threshold, grouping the plurality of time-frequency tiles into sets of frequency-adjacent time-frequency tiles, and for each set of frequency-adjacent time-frequency tiles in the frame: counting a number of flagged time-frequency tiles, and attenuating all of the time-frequency tiles in the each set if the number exceeds a noise bin count threshold to thereby reduce noise in the sound signal.