An audio circuit includes an amplifier, a voltage sensor, a current sensor, and an excursion control circuit. The voltage sensor is coupled to an output of the amplifier. The current sensor is coupled to the output of the amplifier. The excursion control circuit is coupled to the amplifier, the voltage sensor, and the current sensor. The excursion control circuit includes back electro-magnetic force (EMF) measurement, a back-EMF model, and excursion protection. The back-EMF measurement is to measure back electro-magnetic force of a speaker based on voltage measurements received from the voltage sensor and current measurements received from the current sensor. The back-EMF model is updated based on measurements of the back-EMF and is converted to an excursion model. The excursion protection is to limit amplitude of audio signal provided to the amplifier based on the excursion model of the speaker and amplitude of an audio input signal.

Wireless receivers and related methods with interferer immunity are disclosed. The receiver includes a receive (RX) front-end, a power level detector, and an automatic gain controller (AGC). The RX front-end includes circuit(s) having variable gains, and the power level detector outputs a power level indicator. The AGC receives the power level indicator and outputs the gain settings to the variable-gain circuits within the RX front-end. Further, the AGC is configured to adjust the gain settings within a first gain range when not receiving data frames and to adjust them within a second gain range when receiving data frames. The second gain range is a restricted version of the first gain range. Further, the AGC can be configured to detect and store gain settings within a sliding time window when data frames are not being received and to use these stored gain settings to determine the second gain range.

A system and method for digital processing including a gain element to process an input audio signal, a high pass filter to then filter the signal and create a high pass signal, a first filter module to filter the high pass signal and create a first filtered signal and a splitter to split the high pass signal into two high pass signals. The first filter module filters one high pass signals before a first compressor modulates the signal or a high pass signal to create a modulated signal. A second filter module filters the modulated signal to create a second filtered signal that is processed by a first processing module including a band splitter that splits the signal into low and high band signals that are then modulated by compressors. A second processing module processes the modulated low and high band signals to create an output signal.

A half duplex amplifier for a cable network.

A system and method for digital processing including a gain element to process an input audio signal, a high pass filter to then filter the signal and create a high pass signal, a first filter module to filter the high pass signal and create a first filtered signal and a splitter to split the high pass signal into two high pass signals. The first filter module filters one high pass signals before a first compressor modulates the signal or a high pass signal to create a modulated signal. A second filter module filters the modulated signal to create a second filtered signal that is processed by a first processing module including a band splitter that splits the signal into low and high band signals that are then modulated by compressors. A second processing module processes the modulated low and high band signals to create an output signal.

Systems, devices, and methods are described herein for adjusting a relationship between dialog and non-dialog signals in an audio program. In an example, information about a long-term dialog balance for an audio program can be received. The long-term loudness dialog balance can indicate a dialog-to-non-dialog loudness relationship of the audio program. A dialog loudness preference can be received, such as from a user, from a database, or from another source. A desired long-term gain or attenuation can be determined according to a difference between the received long-term dialog balance for the audio program and the received dialog balance preference. The long-term gain or attenuation can be applied to at least one of the dialog signal and the non-dialog signal of the audio program to render an audio program that is enhanced according to the loudness preference.

Aspects are directed to an amplifier circuit including a signal processing circuit and a calibration circuit. In certain specific embodiments, the signal processing circuit includes a signal combiner and a closed-loop feedback path, and the signal processing circuit is designed to provide a loop transfer function for a derived signal partly representing contributions from an audio input signal, a control or pilot signal having a target frequency range, and a calibration signal. The signal combiner is designed to combine aspects of the control or pilot signal and aspects of the audio input signal, and the calibration circuit is designed to adjust an effective gain of the derived signal in response to whether a unity-gain frequency of a signal in the closed-loop feedback path, as provided via the loop transfer function, is higher or lower than the target frequency range. Consistent therewith and in yet more specific embodiments, such an amplifier circuit can define the target frequency range relative to the transfer function and an associated unity-gain frequency.

An audio framework for acoustic feedback suppression. One example portable communication device includes a microphone, a loudspeaker, and an electronic processor. The electronic processor receives an acoustic signal, including an audible component and an ultrasonic component, from the microphone. The electronic processor splits the acoustic signal into a first stream and a second stream identical to the first stream. The electronic processor is removes the ultrasonic component from the first stream to generate a filtered audio stream, and passes the filtered audio stream to a sound server. The electronic processor removes the audible component from the second stream to generate a received ultrasonic stream, and compares the received ultrasonic stream to a transmit ultrasonic stream to determine an acoustic distance. The electronic processor determines an attenuation level based on the acoustic distance, and adjusts an audio component of the portable communication device based on the attenuation level.

The invention relates to a method, comprising receiving a first audio signal during an application execution in an apparatus, determining a volume level of a volume control interface for controlling a volume level of the first audio signal, controlling processing the first audio signal by at least one digital signal processing algorithm determined on the basis of the determined volume level of the volume control interface for controlling the volume level of the first audio signal, and outputting the controlled processed first audio signal at the determined volume level of the volume control interface. The invention further relates to an apparatus and a computer program product that perform the method.

A system and a method provide for protecting a loudspeaker from thermal and/or mechanical failure by monitoring for over-temperature and over-power conditions. The system generates a first gain from a first speaker protection controller in response to a driving voltage and/or a driving current of a loudspeaker, and generates a second gain from a second speaker protection controller in response to the driving voltage and/or a driving current of the loudspeaker, if the temperature exceeds a thermal limit or if the power exceeds a maximum power. The system applies the second gain to an audio signal to lower the audio signal if the first speaker protection controller fails.