Abstract: There is disclosed an audio playback system including a loudspeaker, a microphone and a means for implementing a method of detecting a fault which includes the generation and analysis of a specific ultrasound reference signal. The presence of the ultrasound reference signal can be detected on the microphone signal, and the signal-to-noise ratio can be estimated during the reference signal playback so that the volume of the reference signal can be adapted if necessary. The reference signal is a multi-sinusoidal signal which, when averaged over time increases the expected signal-to-noise ratio, and hence, the power of the detector.

Abstract: A method of generating an audible alert by a digital audio system configured to operate in a first operating mode and a second operating mode is described. An alert signal is generated or received. One or more segments of the generated or received alert signal is processed. The processed alert signal is then analysed to define the operating mode of the digital audio system. In the first operating mode, the alert output signal includes at least the alert signal. In the second operating mode, the alert output signal includes at least the processed alert signal.

Abstract: An audio-haptic signal generator for a haptic system including an amplifier coupled to a haptic actuator is described. The audio-haptic signal generator includes an audio input configured to receive an audio signal; a haptic input configured to receive a haptic signal and a controller configured to receive to at least one of the haptic signal, an amplifier state and a haptic actuator state. A mixer is coupled to the audio input and the haptic input. The mixer has an output configured to be coupled to a haptic actuator. The controller controls the mixer to process the audio signal dependent on at least one of a characteristic of the haptic signal, an amplifier state, and a haptic actuator state. The mixer is configured to mix the haptic signal and processed audio signal on to output the mixed haptic signal and processed audio signal.

Abstract: An apparatus and a method for generating a voice coil actuator (VCA) signal is described. A drive signal is generated to drive the VCA and a resulting current signal from the VCA detected. The frequency of the drive signal is adapted in response to detecting an asymmetry in the current signal.

Abstract: A signal processor and method of signal processing for a radio receiver is described. An input signal is received together with a spectral repetition interval value of an interferer signal. An interference reference signal is generated from the received spectral repetition interval value and the received signal. The received signal is adapted using the generated interference reference signal.

Abstract: An audio processor and method of audio processing for an amplifier system is described. The audio processor may receive an audio signal and adapt the audio signal generating a time varying offset. The time varying offset may be combined with the audio signal resulting in a shifted the audio signal level. The processed audio signal may also be clipped to remove the negative samples values. The processed signal may be used to drive an amplifier designed to only accept positive (or negative) signals such as a class C amplifier.

Abstract: There is disclosed an audio playback system including a loudspeaker, a microphone and a means for implementing a method of detecting a fault which includes the generation and analysis of a specific ultrasound reference signal. The presence of the ultrasound reference signal can be detected on the microphone signal, and the signal-to-noise ratio can be estimated during the reference signal playback so that the volume of the reference signal can be adapted if necessary. The reference signal is a multi-sinusoidal signal which, when averaged over time increases the expected signal-to-noise ratio, and hence, the power of the detector.

Abstract: A method and apparatus are described for aligning cross-faded audio signals using beats. In an embodiment, a controller includes a cross-fade module having at least first and second audio inputs and an audio output port to provide an audio output signal to an external audio reproduction system. A control signal determines whether to provide the first or the second audio signal to the audio output, and the cross-fade module cross-fades the audio output signal from one audio signal to the other audio signal. A beat alignment module determines a delay between a first beat of the first audio signal and a second beat of the second audio signal, and a delay module delays either the first or the second audio signal to compensate for the delay into the cross-fade module.

Abstract: An audio-haptic signal generator for a haptic system including an amplifier coupled to a haptic actuator is described. The audio-haptic signal generator includes an audio input configured to receive an audio signal; a haptic input configured to receive a haptic signal and a controller configured to receive to at least one of the haptic signal, an amplifier state and a haptic actuator state. A mixer is coupled to the audio input and the haptic input. The mixer has an output configured to be coupled to a haptic actuator. The controller controls the mixer to process the audio signal dependent on at least one of a characteristic of the haptic signal, an amplifier state, and a haptic actuator state. The mixer is configured to mix the haptic signal and processed audio signal on to output the mixed haptic signal and processed audio signal.

Abstract: An audio-haptic signal generator for a haptic system including an amplifier coupled to a haptic actuator is described. The audio-haptic signal generator includes an audio input configured to receive an audio signal; a haptic input configured to receive a haptic signal and a controller configured to receive to at least one of the haptic signal, an amplifier state and a haptic actuator state. A mixer is coupled to the audio input and the haptic input. The mixer has an output configured to be coupled to a haptic actuator. The controller controls the mixer to process the audio signal dependent on at least one of a characteristic of the haptic signal, an amplifier state, and a haptic actuator state. The mixer is configured to mix the haptic signal and processed audio signal on to output the mixed haptic signal and processed audio signal.

Abstract: In one example, a communications circuit processes an amplitude modulated signal by using a first circuit having signal paths to process an amplitude modulated signal as represented by an in-phase component and by a quadrature component, and by using a second circuit to discern random noise pulses from the quadrature component of the amplitude modulated signal. In response, the second circuit generates an estimate of overall noise representing the random noise pulses in the amplitude modulated signal. In the above and more specific examples, the random noise pulses may appear as pulses which overlap with, in terms of time and bandwidth of frequency spectrum, information of the amplitude modulated signal, and the first and second circuits may be part of an RF radio receiving the amplitude modulated signal from an antenna.

Abstract: A method and apparatus are described for aligning cross-faded audio signals using beats. In an embodiment, a controller includes a cross-fade module having at least first and second audio inputs and an audio output port to provide an audio output signal to an external audio reproduction system. A control signal determines whether to provide the first or the second audio signal to the audio output, and the cross-fade module cross-fades the audio output signal from one audio signal to the other audio signal. A beat alignment module determines a delay between a first beat of the first audio signal and a second beat of the second audio signal, and a delay module delays either the first or the second audio signal to compensate for the delay into the cross-fade module.

Abstract: In one example, a communications circuit processes an amplitude modulated signal by using a first circuit having signal paths to process an amplitude modulated signal as represented by an in-phase component and by a quadrature component, and by using a second circuit to discern random noise pulses from the quadrature component of the amplitude modulated signal. In response, the second circuit generates an estimate of overall noise representing the random noise pulses in the amplitude modulated signal. In the above and more specific examples, the random noise pulses may appear as pulses which overlap with, in terms of time and bandwidth of frequency spectrum, information of the amplitude modulated signal, and the first and second circuits may be part of an RF radio receiving the amplitude modulated signal from an antenna.

Abstract: An apparatus and a method for generating a voice coil actuator (VCA) signal is described. A drive signal is generated to drive the VCA and a resulting current signal from the VCA detected. The frequency of the drive signal is adapted in response to detecting an asymmetry in the current signal.

Abstract: A controller for an audio system. The audio system comprising an audio processor and an amplifier. The controller is configured to: receive an amplifier-operating-condition-signal representative of an operating condition of the amplifier; receive a maximum-threshold-value; and generate control signaling based on the amplifier-operating-condition-signal and the maximum-threshold-value, wherein the control signaling is configured to set an operating parameter of the audio processor.

Abstract: An apparatus and method for speech communication is described. An audio transmit processor captures at least two audio signals from an audio source, and processes the at least two audio signals to provide a mono audio signal and a non-audio signal comprising spatial information representative of the direction of the audio source. The audio transmit processor combines the non-audio signal with the mono audio signal by watermarking; and transmits the watermarked audio signal. An audio receive processor receives a watermarked audio signal and extracts a mono audio signal and a non-audio signal comprising spatial information from the watermarked audio signal. The audio receive processor processes the mono audio signal and spatial information to generate at least two output audio signals.

Abstract: A method and apparatus for generating a haptic signal is described. An audio signal is received and an event signal comprising a plurality of pulses is determined from a characteristic of the audio signal. A haptic output signal is generated by combining a haptic pattern triggered by a first pulse and at least one further substantially identical haptic pattern triggered by at least one further pulse.

Abstract: An audio-haptic signal generator for a haptic system including an amplifier coupled to a haptic actuator is described. The audio-haptic signal generator includes an audio input configured to receive an audio signal; a haptic input configured to receive a haptic signal and a controller configured to receive to at least one of the haptic signal, an amplifier state and a haptic actuator state. A mixer is coupled to the audio input and the haptic input. The mixer has an output configured to be coupled to a haptic actuator. The controller controls the mixer to process the audio signal dependent on at least one of a characteristic of the haptic signal, an amplifier state, and a haptic actuator state. The mixer is configured to mix the haptic signal and processed audio signal on to output the mixed haptic signal and processed audio signal.

Abstract: A method and apparatus of acoustic processing for a mobile device having a haptic actuator is described. A vibration drive signal for driving a haptic actuator is received. A vibration noise output from a haptic actuator is detected. At least one vibration noise metric from the detected vibration noise output and the vibration drive signal is generated. The vibration noise output level is adapted in dependence of the at least one vibration noise metric.

Abstract: An audio processing circuit is described. The audio processing circuit includes at least one input configured to receive a primary audio signal and a feature generation signal. A feature model estimation circuit is configured to model and output a feature model signal of the primary audio signal. A feature generation circuit is coupled to the feature model estimation circuit and is to receive the feature model signal and the feature generation signal and, in response to the feature model signal, modify the feature generation signal; and output a modified representation of the feature generation signal that is more similar to the primary audio signal.