Abstract: A method of calibrating a feedback-based noise cancellation system of an ear device may involve obtaining a measured plant response of the ear device, obtaining a reference plant response value and determining a plant response variation between the reference plant response value and a value corresponding to the measured plant response. The method may involve obtaining a measured a coupler response of the ear device, obtaining a reference coupler response value and determining a coupler response variation between the reference coupler response value and a value corresponding to the measured coupler response. The method may involve determining, based at least in part on the plant response variation and the coupler response variation, a microphone signal gain correction factor and applying the microphone signal gain correction factor to ear device microphone signals that are input to a feedback loop of the feedback-based noise cancellation system.

Abstract: A method of calibrating a feedback-based noise cancellation system of an ear device may involve obtaining a measured plant response of the ear device, obtaining a reference plant response value and determining a plant response variation between the reference plant response value and a value corresponding to the measured plant response. The method may involve obtaining a measured a coupler response of the ear device, obtaining a reference coupler response value and determining a coupler response variation between the reference coupler response value and a value corresponding to the measured coupler response. The method may involve determining, based at least in part on the plant response variation and the coupler response variation, a microphone signal gain correction factor and applying the microphone signal gain correction factor to ear device microphone signals that are input to a feedback loop of the feedback-based noise cancellation system.

Abstract: This invention provides an audio speaker with improved physical safety isolation between a voice coil and other electrically live elements.

Abstract: This invention provides an audio speaker with improved physical safety isolation between a voice coil and other electrically live elements.

Abstract: In a first aspect, the invention provides an audio amplifier. A regulator reference signal corresponding to an input audio signal is generated by regulator reference generator. A power signal is generated corresponding to the regulator reference signal by a voltage regulator. A compensation block also uses the input signal, or a delayed version of the input signal to generate a modulation control signal. A modulator generates a modulated signal in response to the modulation control signal. An output stage combines the power signal and the modulation signal to provide an output audio signal corresponding to the input audio signal. The compensation block may be a forward compensation block configured to compensate for characteristics of the regulator reference generator or the voltage regulator or both, and possibly other components of the amplifier. In other embodiments, the compensation block may be part of a feedback compensation loop.